OP, yes I was aware you stated this advice was not for weight loss.
My "issue" is the amount of effort both of you are putting on calories in, calories out...eating this and eating that. She may not be competing, but that doesn't mean she isn't comparing herself to her non-tumbling friends as well as the other girls at the gym. Plus, while I understand your bulimia is no longer an issue directly (as in you no longer display the obvious signs of bulimia), you may still have those concerns in the back of your head that you aren't even aware of.
And you keep emphasizing how beautiful and strong she is now that she has slimmed down a bit and grew a bit. Well obviously she has been doing something right. And, she is only 12 - her body will be going through lots of changes that will probably include gaining weight, losing weight, etc.
I'm sorry - I know that I am reading into this way more than you have intended. And that's my issue with diet and weight loss. I tend to read between the lines and see what may or may not be there. But I don't mean to offend you.