Lil,
You're hit the nail on the head!!!! Not just for the reasons you've stated, but also because she would have no power over anyone else if she were to leave. Most others would tell her to "buzz off" if she behaved in her usual fashion with them.

Sorry Bube, but if you want her to leave, you'll have to force her out and probably get a restraining order to keep her out!!!! This...I know you won't do.