I'm kinda confused about my dwarf hamsters???

I've asked questions about these hamsters before because I'm a first time hamster owner. One of my hamsters is in a cage with her baby, but she picked on her and attcked her 24/7. I put a divider in between them but they do nothing but try to get past it so they can be together. They got past it last night and started fighting for about twenty straight seconds then stopped and didn't fight again. The younger one has dried blood covering the fur above her tail. I'm not sure what do. If I put them together one could kill the other, but if I keep them separated, then they'll do nothing but try to be together. Please help. Thanks!