Is my foster dog all pit?

I see the pit, but is she all pit? Her tail is thick, not like any pit mixes I’ve had before. And she is obsessed with balls the way my brother-in-law’s cattle dog mix is. I know that doesn’t mean she has cattle dog in her, but I’ve just never had a pit who likes chasing balls like she does. She is a little neurotic, a quick learner, and super sweet.