Make her move foreward.  Rearing is just stuck feet.  When she goes up, don't pull straight, pull to the side and lunge her off vigorously.   Cracking the shins with a whip works well, or a few good stinging swipes on the belly.  She can't rear while running foreward (at least not well)  If she falls over, fine.  Try not to make it on concrete.  Sometimes falling over scares them out of it rearing since it doesn't get them what they want.....rearing is a dangerous situation, do whatever it takes to get it stopped.  You don't need a hoof coming down on your head.

Amanda 

Get her feet moving.  In order to rear they have to pretty much stop in place.  Don't get behind her, use "pressure" by taking the end of the longe rope and flicking it at her hip.  If you move her hips, you can move her front end.

I strongly suggest you start her over, she has lost respect from you and is capable of seriously hurting her. 

I don't agree with striking the legs or belly, this is not solving why she is rearing.  She needs to learn respect. 

I would get a Clinton Anderson or Craig Cameron video or book. I don't agree 100% with their methods, but I take some from both.  I just saw them at Equine Affaire and firmly believe in their ideologies on gaining respect.

Keep the feet moving.  You have to get them focused on you, and not on misbehaving. 

Whipping and striking a horse will not solve the problem,but only reinforce the fear they exhibiting.

A horse rears because they are afraid and something is causing them to be defensive.  horses are fight or flight animals.  You are taking her away from mom or where she feels in her comfort zone so hence the rearing, it is her way of demonstrating she doesn't respect you, she doesn't feel safe with you, and she is fighting because she is afraid.

I truly wish you luck, but what I would do is get a hold of someone who knows how to deal with babies in a calm non threatening manner and have them help you learn how to gain her respect.