With that mix of breeds, she is considered a grade horse, but it may be possible to have her registered as a 1/2 Arab if you can prove breeding. There are other members who will be more familiar with that registration.
As for what she is capable of becoming, that has more to do with her build, her mind, and the discipline you are interested in. We would certainly need more information including pictures.
With that mix I would think that she may have the potential to do many things, but isn't bred for anything in particular. I don't think it's really possible to know until she's older and you can assess her temperament and conformation.
Wait until she's 3 or 4 and broken in and see what she's good at.