My question is why resting 2 months (at least from impact, etc) is out of the question?? She is 7 years old and potentially has many years ahead of her in this sport (especially with her hard work and talent), why risk it?? If she doesn't rest now, she could end up being forced to miss much more later and at what benefit?
This injury might seem like it isn't a big deal, but it can be if it is ignored. I say that with young kids especially, it is better to err way on the side of caution. She can still do a lot of things in the gym, bars, upper body conditioning, and possibly low impact things. I would see if she can see PT and get some rehab recommendations. I would take this serious, otherwise it can become a long term nagging problem, when it could have been avoided altogether. I am sure she won't be happy with the decision (mine wasn't when I made her sit out for an injury that wasn't even proven), but she will learn that her body and health important and that you need to listen to your body.
And I know it is tough for the gymmie and mom. My kid missed a total of almost 6 weeks due to a wrist injury (couldn't do bars, handstands, tumbling, etc). She lost skills and had to get them back, she was bored at practice sometimes, but she did it and I know that it was the right decision. She is only 8 and I didn't want to get her a chronic injury so young. It isn't fun being the tough guy either. I made sure coaches knew I didn't want her tumbling, doing anything on the wrist, etc.