Wow, that's pretty bad. Maybe you should get a professional trainer on her for a few days. Did you not ride her before you got her?

That kind of sounds like a old horse of mine (Rowdy,you can find pictures of him if you do a search) he was a 3 yr old QH and he was good when we tried him but when we got him to our place he was kind of bad.

Just don't let her get away with ANYTHING, if she throws you off get back on her and show her thats not ok. I got thrown off Trigger (first pony) and I got right back on him with a severly sprained ankle, I was told even if you in alot of pain get back on because it will start to get into their heads right away that it's ok to do that.