I had a lesson yesterday and my coach got on her to see if there was a really big problem with her. It turns out that it's just that it's srping and she used to do this with the other girl who rode her too. All I have to do is be extra firm with her and if and when she bucks, do not take that. Hopefully this will fix before my first show!
PS - She's been following me again! =) ... I guess that I was just over reacting at that part! Lol.