C.O.
why are you letting yourself get sucked into her games? That's EXACTLY what this is. A GAME.
She's got you and everyone else believing she's got some super-duper close relationship with the boss. So they socialize on the weekends. The boss needs to be able to separate business from pleasure. If you can document her 'stuff' - great. Take it to the boss. If you can't - fine - still go to the boss if you feel that strongly about it. I personally wouldn't. Why? Because.....
She's not your friend. She's your co-worker. Go to work. Do your job. Do it to the best of your ability and don't fall for her games or antics. When she sees it's not working - she will stop.
She said you haven't offended her. So press on. Don't let her get to you and don't give her free rent in your head. You can be nice. You can be cordial but you do NOT have to play her games. If you have to talk to her about work - great. If not - then don't.
You are the adult. Act like it (not saying you aren't) just reiterating it.
If you don't think you can handle it anymore - get your resume together and get it out and start looking for a new job.