H.H.
wow...i went thru the same thing with my son at that age except i was a single parent. they do grow out of it and you did nothing wrong. you are her safe person so she feels safe to express herself and at that age, that's the way she expresses herself. i'm not saying it's right, but i am saying you're not at fault. what finally worked for me, and it took a while to find, was to have him earn his favorite things. time outs did not work for us at all. loosing me for a little while after he'd hurt me helped too. since you have a back up (or when you do), when she hurts you, leave. say i don't play with someone who hurts me. this didn't work much for me, but it gave me a little sanity. then, find tv shows, computer games, favorite toys, something that she can only play with on days when she has not hurt you. you might start off, she can use it at noon if you make it thru the morning and then again at night and then, double the time at night if she makes it thru the whole day but delete the morning...something...so she has to go more and more time not hitting. when she goes to hurt you, stop her and say "use your words". give her the words if necessary, "you are mad at mommy because she isn't letting you have a cookie." "it's ok to say that and it's ok to be mad, but you may not hurt". it doesn't work right away, but if you commit to it, it will eventually. sorry you have to go thru this, but, like i said, she will grow out of it and then you'll be onto bigger and badder : ) good luck!