She is gorgeous. She is still young and these things will happen because she is still green. Glad you are both okay. I am sure with more time and experience she will be perfect. Boerperde generally bring that level headedness to the TB crossing.
I love the Boerperd breed. They can have the stamina of an arab, but with more bone, so are stronger in my opinion, are usually well put together horses conformation wise, they are hardy little horses, they have great personalities, they are also intuitive and intelligent horses, learning quickly and instinct-fully looking after their rider once they have bonded with you. I guess your bonus is she is crossed with a TB, so you have the fun of TB hotness and speed element added to the mix. :)