To the person who wrote about their 9-year-old half-sister:

I have the type of diabetes in question, and I can tell you that your half-sister needs a new doctor. The term “juvenile diabetes” is outdated, for one (the correct term is “type one diabetes”), and being fat isn’t even considered a risk factor. Type one diabetes does cause weight gain in a lot of the people who have it, but only when it’s well-controlled. When it hasn’t been diagnosed and isn’t being treated, it actually causes weight loss.

Being fat is popularly considered a risk factor for type two diabetes (although recently there’s been some debate about that), but it’s almost unheard-of in a child her age without an extensive family history of the disease, and you probably don’t need to be worried about it, especially if she’s active like it sounds like she is.