I agree with everyone's posts that you have a very well bred mare that should excel in anything you ask of her!
She should make a really nice cowhorse with her cutting lines but should also excel in speed events as her bloodlines go back to a lot of older QH race lines (+ the added TB).
A lot a barrel racers like the cow/running mix as they tend to have a more solid bone to them and can handle the constant pounding of barrel racing better than a fine boned horse can.
Have you tried her on cows yet? She could make a really nice penner
Yep, I've used her on my uncle's ranch and used her in team cutting(not the same I know). Like barrels she needs training to be better.