I'm sorry to hear that! I would NOT try nail polish. I tried it, and it didn't work, even though some other websites said it would.

You can buy actual acetone (paint thinner) from a hardware store. But if the damage is that major, you may not be able to stick her back together easily.

There are some services which repair Breyers for a fee, although they can be hard to find. Here is one I found online:

http://www.modelhorserepair.com/services.htm