The investigators will capture adolescent perceptions of feasibility of the entire intervention in the Post-Intervention Adolescent Interview. The quantitative and qualitative data related to this primary mixed methods outcome (Feasibility of the Intervention) will be integrated together at the data analysis phase.

The investigators will capture parent perceptions of feasibility of the entire intervention in the Post-Intervention Parent Interview. The quantitative and qualitative data related to this primary mixed methods outcome (Feasibility of the Intervention) will be integrated together at the data analysis phase.

The investigators will capture adolescent perceptions of feasibility of the entire intervention in the Reflection Entries. The quantitative and qualitative data related to this primary mixed methods outcome (Feasibility of the Intervention) will be integrated together at the data analysis phase.

The investigators will capture parent perceptions of feasibility of the entire intervention in the Reflection Entries. The quantitative and qualitative data related to this primary mixed methods outcome (Feasibility of the Intervention) will be integrated together at the data analysis phase.

The investigators will calculate the recruitment rate of the study: the numerator will be the number of dyads that are enrolled in the study (i.e., signed consent) and the denominator will be the number of adolescent-parent dyads who complete the Contact Information Form or reach out to the investigator about the study. This quantitative outcome will help to gather an understanding of the feasibility of the research procedures and methods of the study and will be collected through Qualtrics via the Reflection Entries. The results regarding this outcome will be reported in a descriptive summary at the end of the study and integrated with the other data related to the feasibility of the research procedures and methods, both qualitative and quantitative.

The investigators will calculate the completion rate of the study: the numerator will be the number of dyads that complete the study (i.e., post-intervention measures) and the denominator will be the number of dyads that are enrolled in the study (i.e., signed consent). This quantitative outcome will help to gather an understanding of the feasibility of the research procedures and methods of the study and will be collected through Qualtrics via the Reflection Entries. The results regarding this outcome will be reported in a descriptive summary at the end of the study and integrated with the other data related to the feasibility of the research procedures and methods, both qualitative and quantitative.

The investigators will calculate the proportion of missing data (i.e., individual questions, entire surveys) across all data collection measures. This quantitative outcome will help to gather an understanding of the feasibility of the research procedures and methods of the study. The results regarding this outcome will be reported in a descriptive summary at the end of the study and integrated with the qualitative data regarding this outcome at the data analysis stage.

The investigators will calculate the duration of time it takes participants to complete each data collection measure (i.e., individual surveys, interviews). This quantitative outcome will help to gather an understanding of the feasibility of the research procedures and methods of the study. The results regarding this outcome will be reported in a descriptive summary at the end of the study and integrated with the qualitative data regarding this outcome at the data analysis stage.

The investigators will capture adolescent perceptions of the feasibility of the research procedures and the methods using the Post-Intervention Adolescent Interview (specifically, perceptions of response burden and measure relevance). The quantitative and qualitative data related to this secondary mixed methods outcome (Feasibility of the Research Procedures and Methods) will be integrated together at the data analysis phase.

The investigators will capture parent perceptions of the feasibility of the research procedures and the methods using the Post-Intervention Parent Interview (specifically, perceptions of response burden and measure relevance). The quantitative and qualitative data related to this secondary mixed methods outcome (Feasibility of the Research Procedures and Methods) will be integrated together at the data analysis phase.

The investigators will capture the experience of the intervention from the adolescent using the Reflection Entries and the Post-Intervention Adolescent Interview. Specifically, this will include asking about their self-reported experience, preferences for the components, and feedback about the intervention.

The investigators will capture the experience of the intervention from the parent using the Reflection Entries and the Post-Intervention Parent Interview. Specifically, this will include asking about their self-reported experience, preferences for the components, and feedback about the intervention.

The investigators will re-contact the adolescents in the study to capture the proportion of adolescents that transitioned to adult care to see if they enrolled and are continuing to attend adult care. This quantitative outcome will be reported as a proportion.

The investigators will capture the adolescent's self-reported range and severity of their eating disorder symptoms before and after the adolescent completes the intervention using the Eating Disorder Examination Questionnaire (EDE-Q 6.0). This measure contains 22 Likert-scale items (from 0 to 6). The minimum total score for these questions is 0 and the maximum is 132. Higher scores indicate an increased range and/or severity of eating disorder symptoms. The measure also contains 6 self-report questions where respondents are asked to report the frequency of a behaviour (e.g., restricting) and their height, weight, and menstrual patterns (if applicable).

Repeated Measures design will be used to analyze the mean difference in total score of this measure from baseline to post-intervention. A descriptive summary of the responses to the differently-formatted questions (items related to behaviour frequency, height, weight, and menstrual patterns) will be reported as well.

The investigators will capture the adolescent's self-reported level of readiness for transition to adult care before and after the adolescent completes the intervention using the Transition Readiness Assessment Questionnaire (TRAQ). This skill-focused tool contains 20 Likert-scale questions (from 1 to 5 in increments of 1) organized by 5 domains: medication management, appointment management, health issue tracking, interactions with providers, and daily activity management. The minimum total score of this tool is 20 and the maximum total score is 100. Higher scores indicate increased readiness for transition.

Repeated Measures design will be used to analyze the mean difference in total score of this measure from baseline to post-intervention.

The investigators will capture the adolescent's self-reported awareness of their health condition and ability to make decisions relevant to their healthcare needs before and after the adolescent completes the intervention using the Self-Management Skills Assessment Guide (Youth Report) (SMSAG-Y). This measure contains 21-identically structured Likert-scale items (from 1 to 5 in increments of 1). The minimum total score of this tool is 21 and the maximum total score is 105. Higher scores indicate increased awareness and ability surrounding their eating disorder.

Repeated Measures design will be used to analyze the mean difference in total score of this measure from baseline to post-intervention. Additionally, since this measure will also be completed by the parent, the scores will compared to assess similarities and differences between their perspectives.

The investigators will capture the adolescent's self-reported readiness and motivation to change various eating disorder behaviours before and after the adolescent completes the intervention using the Eating Disorders Readiness Ruler (ED-RR). The first 9 items (from 1 to 10) measure readiness to change (minimum score of 9 to a maximum of 90). Higher scores for these items indicates increased willingness to change. The last 9 items measure the extent to which the change is being made for others versus for themselves on a scale from 10% to 100%. A "controlled motivation" score of 1 is assigned to responses from 0 to 30% (change is for others) and an "autonomous motivation" score of 1 is assigned to responses from 80-100% (change is for themselves). Total scores for each motivation type are computed, ranging from 0 to 9.

Repeated Measures design will be used to analyze the mean difference in the total score for each domain from baseline to post-intervention.

The investigators will capture the parent's self-reported carer burden and impact of eating disorder symptoms on parents' lives before and after the parent completes the intervention using the Eating Disorders Symptom Impact Scale (EDSIS). This measure has 24 Likert-scale items (from 0 to 4 in increments of 1) on four domains: nutrition, guilt, unregulated behaviour, and social isolation. The minimum total score of this measure is 0 and the maximum total score is 96. Higher scores indicate increased burden or impact of their child's disorder on the respondent.

Repeated Measures design will be used to analyze the mean difference in total score of this measure from baseline to post-intervention.

The investigators will capture the parent's self-reported needs as the carer of an individual with an eating disorder before and after the parent completes the intervention using the Carers Needs Assessment Measure (CaNAM). This tool contains 32 Likert-scale items (from 0 to 2) across three domains: information about eating disorders, support from people/organizations, and support for yourself (minimum total score of 0 and maximum of 64). Higher scores indicate that the respondent is satisfied with the resources/information they've received. The final domain contains 15 yes/no questions regarding areas where the respondent may appreciate help. The 4 remaining open-ended questions ask the respondent elaborate upon each domain.

Repeated Measures design will be used to analyze the mean difference in total score and subscales of this measure from baseline to post-intervention. A descriptive summary will be used to summarize the responses to the open-ended questions.

The investigators will capture the parent's self-reported self-efficacy and collaboration among carers of patients with an eating disorder before and after the parent completes the intervention using the Patient and Carer Collaboration Scale - Carer (PACCS-C). This measure is comprised of 33 Likert-scale questions (from 0 to 100 in increments of 10) that relate to four constructs: hope, self-care and compassion, externalization of the eating disorder, and boundaries. The minimum total score of this measure is 0 and the maximum total score is 3300. Higher scores indicate better outcomes (e.g., setting strong boundaries, increased hope).

Repeated Measures design will be used to analyze the mean difference in total score and subscales of this measure from baseline to post-intervention.

The investigators will capture the parent's self-reported perception of their child's awareness of their health condition and the child's ability to make healthcare decisions before and after the parent completes the intervention using the Self-Management Skills Assessment Guide (Parent Report) (SMSAG-P). This measure contains 22-identically structured Likert-scale items (from 1 to 3 in increments of 1) where higher scores indicate the parent's increased belief in their child's awareness and ability surrounding their eating disorder. The minimum total score of this tool is 22 and the maximum total score is 66.

Repeated Measures design will be used to analyze the mean difference in total score of this measure from baseline to post-intervention. Additionally, since this measure will also be completed by the adolescent, the scores will compared to assess similarities and differences between their perspectives.

In the baseline measure package, that includes the adolescent outcome measures above, the investigators will ask the adolescent their sex, gender, date of birth, school grade, ethnicity, type of eating disorder, length of eating disorder, date of diagnosis, and type of treatment received to date. A descriptive summary of demographic information will be prepared to report this data.

In the baseline measure package, that includes the parent outcome measures above, the investigators will ask the parent their sex, gender, age, ethnicity, relationship to adolescent (e.g., parent, stepparent, guardian), marital status, household income, highest level of education achieved, number of people in household, number of children cared for, number of children (apart from participating adolescent) who have an eating disorder and corresponding details, and whether the parent has had an eating disorder and corresponding details. A descriptive summary of demographic information will be prepared to report this data.