When to tell 9 year old that she is adopted?
My 9 year old niece (biological child of my brother) was adopted at 2 months of age by my sister and her husband. The biological parents were arrested and the baby was placed into foster care until my sister could get from San Diego to Santa Rosa to take possession of her while they were in jail. After that, the monthly visitations proceeded for almost a year, with the intent of reunification, but the biological parents failed their requirements and eventually signed over parental rights to my sister and brother in law.
My niece now has an amazing life! She is the youngest of 3 kids, happy, smart and well-adjusted. She lives less than a mile from grandma, and enjoys a close relationship with her, as well as with me and my family here in the Bay Area. She has a huge extended family and her life is full of love.
My question is in relation to the timing of one day telling her that she is adopted (and that she has at least 2 older siblings that we are aware of). After a family reunion this summer, some of our family members reported that she told them something like "I can't figure this out -- I don't look like anybody else in my family" which isn't really true, but it is true that she doesn't look much like my sister's other 2 kids.
She will turn 10 in September. Does anybody have experience with telling a child that they're adopted, and what is the best timing for this? I want to be able to help my sister and brother in law in their decision about when and how to tell her.