She's a little bit obsessed but mentally unstable is a bit far.
Then again none of us know about any of their history, she might have very good reason to hate him so much. And I genuinely believe (as Coleen basically admitted on last night's BOTS too) that she thinks he's putting on an act and holding back his true thoughts (as do I actually) so as to appease the public and improve his reputation, and so she's trying her hardest to provoke a reaction to expose the real him.
And I'm certainly not going to complain at that, because if fight night three breaks out because Jim finally explodes, that will really round this series off in style