She looks just...long in general to me. Like her back and neck. I'm not very good at conformation admittedly, but that's just what I see. Long is typically weaker. She also appears to be long in the fetlock which could potentially cause problems. All in all theres no reason why you couldn't train this horse to barrel race, but I wouldn't expect to make a pro horse out of her. Maybe someone else can give you a better critique.