You're in luck. I've actually already written a blog entry about this very problem. In fact, the shetland colt I used in the lesson is just a little older than your filly.
Turning her butt to you and trying to kick is a sure sign of either disrespect or fear. It could be that her dam was an alpha mare, near the top of the herd's pecking order, and that she taught his behavior to her filly. Either way, you need to convince your little gal that you are the boss, not her, and that she needs to trust you and treat you as such. You can do this without hurting her or yourself. It's just a matter of becoming her alpha leader.
You can read the entire lesson (and others!) here:
You're looking for "Dealing with typical horse problems" about 2/3 of the way down the page.
Please let me know if this helps. Remember, there's always more than one way to teach something. If this doesn't work after a few days of trying it, let me know and I'll suggest another lesson to try with her.
And be sure to recommend my hubpage and blog to all your friends with horses. These Natural Training methods work with all sizes of horses!