Molly and milo had a fight

They were fine now there's fur everywhere. I put molly in the puppy pen and tried to put them together again but she just attacked him. I had to climb in and get him out getting a nasty bite on the leg in the process. She bit me so hard that when I lifted my leg she came with it. I don't know what to do. She literally moving the pen trying to get to him

If she isn't spayed that could explain the aggression. Also I would have your male taken to the vet, many animals attack sick animals, and she could be trying to tell you he is sick. Best of luck!