Cat Fight, Cat Fight!!

We have been trying to integrate a new cat into the household. Both the new one and the established one are 12-year-old females. At first the established one was more aggressive and picked fights, but the tide has turned and the newbie is now the aggressor. Their altercations tend to be related to the new one's mood...if she's relaxed and happy there aren't any problems, but if she's ornery or frisky then there is sure to be a dust up.

For years established kitty has slept on top of mother dear all night, gone out about 6 a.m. to patrol her territory and do her business, came back in about 8 a.m. for breakfast, then went back in on top of mom. This morning, newbie must have been looking for trouble because she decided to jump up on the bed. A cat fight ensued directly on my mom's chest complete with hissing, growling, and screaming (that was my mom). Established cat wound up with a bloody nose from a scratch and my mother just about had a heart attack.