Welcome! I hope that your experience here is a pleasant & educational one!
Horses don't understand punishment, but instead will think that you've gone predator/want to kill them, if you start striking them as punishment!
You're going to get differing responses from people here, all of whose qualifications are unknown to you, rendering you unable to decide who, if anyone, has the answer for your particular horse.
There's no generic solution for rearing, anyway, because no horse is generic.
My hope is that you'd get a qualified person to visit & deal with your horse, & help you with the issue.
That said, I commend you for seeing that the filly is looking for a leader. So, you know that if you're the friendly & wise leader, she'll drop the rearing & join up with you.
Last edited by Northern; 06-21-2011 at 05:03 PM.