Trot up to the fence. If she tries to take off hold her as much as so can and then after the fence halt her pivot and do the fence again. It takes a couple times to slow down but it does work. I was training my friends gelding and he was super speedy and not responsive until I tried this it works really good. And if they don't rush the fence and listen to you then be really still and let them continue over the fence and on the rail and try agin.
Seat into Legs into Hands to Soften - dressage, dressage, dressage.