It's jealousy issues if the kid does it and pushes her down the stairs that preemptive murder

Tell the dad.

I feel really bad for you for being mistreated by a ten-year-old, but I honestly don't blame your stepdaughter either. She's 10; she's probably seen Cinderella a bunch of times. Also, as a girl with a single mom (my father died when I was young), I understand what your stepdaughter is feeling. She probably doesn't want change, and most kids whose one parent has left or has passed away, probably don't either. I know I'd feel really awkward around my new stepfather if my mother had chosen to remarry, especially if I had ended up having a younger sibling. Of course that's not and excuse for your stepdaughter's behavior, but I'm just saying that I might understand why she chose to do what she did.

Watch your step ;)

Take that seriously. 10 year olds are capable of killing. Be careful!

Put a cow bell on her. You'll know where she is at all times.

A couple of things. First, the ten year old is acting out because she feels threatened. Make sure her place in the family is reinforced and secure. That said, you need to set the ten year old straight. Talk to your husband first. You two need to be on the same team. Then the two of you establish appropriate boundaries and rules for acceptable behavior regarding how she will treat you. Address her delivering warnings and threats. Make sure the little witch and her daddy know this is far from acceptable. Draw the line in the sand now. She is wrong and you need to address it. She needs to hear her Daddy tell her she was out of line. If you don't address this now her behavior will only get worse. Consequences for bad choices work. Shave her head and take away TV, phone, computer and friends for a month and restrict her to two weeks bread and water. Lack of consequences always leads to an unruly child who defies you at every turn. I suggest that you and the Daddy deliver the consequences together. She needs to see that you and your husband are a team on this. FYI - you should not be afraid of a ten year old. After you turn the tables on her you can deliver one of your own threats. Something like... "If you harm me or the child I will do equal or greater harm to you".

SMACK THE BITCH

This isn't so unusual. Lots of kids feel threatened by a new baby in the house. However, saying she is going to physically harm you is very serious and you should seek counseling. Even at age 10 that is a very extreme reaction. I come from a divorcee house. My dad knocked up my psychopath of a step-mother. I'm not using that term lightly. She threatened my mothers life with a kitchen knife when I was 10. My brother and all of her family except one of her brothers has anything to do with her. I hated her but not the baby. He didn't have any say in the matter.

Should have slap that little .... Lol