If she is not going to hunt get her a good hand held back tension release and have someone show her how to use it. It takes a little practice but they will work better in the long run if she wants to be accurate. Plenty of info on this site and others about them if you don't have anyone to help.

I am small and shoot mostly wrist strap releases and have not had this happen. I would also suggest finding a good shop that will let you try some out and find one that fits well.

I personally like the velcro ones myself. I either put it on before I walk to my stand, or get to my stand early enough that it doesn't matter. And then don't mess with it once I'm in my stand.

Sounds to me like it's too tight.

Paul