Mazzie is like that, with all other birds except Dayo. I actually asked some of my friends about it, because she is really jealous of every other bird. They said she probably senses that out of the whole crew, those two are my babies. Both of them are my angels, Mazzie the sunshine in my life and Dayo is the laughter.
With Maz I have had to develop a system to keep the other birds safe, and still let her play. If they are on a stand, she's across the room on me or another stand. She'll growl and snarl if they even get close, and will attack given half a chance.
Its a slow thing, and it may never be "good". To this day Maz tries to chase Buddy, but he can fly away so its just good for a laugh now. He'll hop over her, land on the other side and give her a raspberry. I know he knows that hes taunting her, and he's enjoying it too!
Prinny might just be one of those extremely jealous birds. Oh, and I don't think its because she was an only bird... Mazzie had two big brothers when we got her... Whitey Ford and my other teil who passed on Pan. She didn't like them either
Athena