My hamster is getting fatter each day she is a female. When we got her she was isolated so I don’t know if she was by a male. When I put her in the cage with a male she fought with him. And lately she has been really agitated kinda. And she has been sleeping during the day and night.

Any animal that is pregnant will sleep more than usual in order to conserve energy. Your hamster may have been exposed to a male prior to you getting her so she could be pregnant. Hamsters gestation period is around 3 weeks, so pay attention to how long she has been this way. If she is pregnant, then it makes sense that she fought with the male hamster. If she isn’t, then she may be a hamster who enjoys being alone or that particular partner didn’t suit her fancy. Good luck with your hamster