daughter hitting

[ChippyChips]

My DD3 has started to hit a lot. and throwing anything she can get her hands on. The problem is it's not just when she's being told off or told no, sometimes its without any reason at all. Just now she has thrown her boot at me, hitting me in the mouth and causing it to bleed.
She's knows it's wrong but still does it.
I'm at the end of my tether with her and don't know where to go fro here. I'm frightened she's going to really hurt me one of these days.

Is she 3 years old or is she your third dd and a different age?

I see parents tolerate this sort of behaviour often, and oddly enough they never do it with me. Why! because they would not dare. As pikapikachu asked is she 3. What ever age she is, it is unacceptable behaviour. Not sure how you discipline, but never do it half-hearted, it must have an impact or it will surely fail. Having a presense and being able discipline DD3 by acting cross, or just being very ascertive, and withdrawing your love until she apologizes, will offer the best chance of success, "but you must be consistant and never let her get away with with it, even if you have to turn the cooker off, be late for school, miss your favourite TV etc".