She's so cute! Get a rope halter and use it consistently. It really helps with my guy. Use pressure until she gives in and release. I used a John Lyons book to guide me in groundwork with my colt and it helped make him really light in hand. He's now 18 hds and wonderful on the ground. Can't start too early with these big guys. A rope halter still works on Cody except when lunging. I don't have a round pen and when cantering he will sometimes get too strong so I have to use a stud chain.