Thought I'd update....

Peanut started acting aggressive when Nibbles came in to the picture- before then it was just her and Buster and she was completely fine. Ever since Nibbles came in to the home Peanut hasn't been very fond of her. I don't think Princess Fatty likes having competition with Buster!

SO, I finally separated Nibbles from them and placed her in her own cage. The problem with Peanut's nasty behavior is somewhat solved. Nibbles cage is directly next to Peanut & Buster's so she can see them, sniff noses, etc - just not provoke Peanut to go nuts. They all seem to be doing just fine and content. Every so often Peanut will chase Buster around in the cage and nip at him - but not as severe as in the past. Earlier today, I let all 3 out of their cages to run around and get some exercise. Everything went alright; Peanut chased Nibbles around with her ears flat back but did not bite. Of course I was quick to stop her and made sure all 3 could run around peacefully. I am surprised Nibbles still has fur on her chin considering she has to ferociously chin everything within her reach!!! I do not believe that Nibbles is unhappy with being separated. She seems to be her usual spunky self, no signs of separation anxiety. She tended to keep to herself when in the cage w/ Peanut and Buster, so I believe she is fine with being alone.

I think the problem is solved. I wish all 3 would just get along though- I hate having them separated, but I think it's best.