Is my horse actually putting her heart out to this, or is she just doing it because i tell her to ?

I have a thoroughbred that i got over a year ago from a place that just wanted to shoot her. I have always loved jumping so since she was my first and only horse, i wanted her to be my amazing jumper . she loved it, her ears would perk up when she turned toward a jump, and she loved that she could start somethign new. She has never jumped before, so i had to teach her. She seemed to be learning. I Wanted to try something new. I set up barrels and she went through them like nothing. She had a blast. Maybe she was a barrel racer before? And when i went back to jumping, something was different, when she was cantering towards a jump, she tureds the corner really sharp and threw her head down, ignored my hands, jumped flat, turned the corner sharp again, and kept going faster, it always threw me off balance. She never did this before. I didnt like the way she was behaving, so i started again, taking her, at a walk, slowly over a low crossrail, then a trot.. until she slowed her speed and took corners nicely.. but now, she doesnt have her usual upbeat, spirited stride. Would she rather barrel race than jump?