BellaOnline Forums Family Step Parenting Step-daughter very challenging

I have been married to my husband for almost 2 years now. He has 2 daughters 10 and 6. We have recently gained primary custody of them and they are now living with us. The 10 year old is pretty good except for the pre-teen attitude every now and then. But the 6 year old is a fight 80% of the time. There are a lot of times where their dad is not around and it is just me and the kids. She knows how to play people especially me. As long as she knows that her dad isn't around or he can't hear she will fight with me about doing what she is told and when she is told. But her attitude is like night and day when her dad walks in the room. I can't figure out how to get the respect even half of the time. I get so frustrated because i know she would do what she is told if it were her dad telling her and not me.
Help?

Come up with a behavior chart. Everytime she back talks or doesn't do something you say give her a check mark. After so many check marks take a privilege away until she earns it back.

She can earn it back by you taking some play money and giving her a dollar everytime she does something without any grief. When she has enough money, a pre-determined amount set by you, she can buy that privilege back.

Once you take that privilege away, the first time she mouths off, she doesn't earn any money for that day.

Or do a level system from Level 4 to Level 0. Level 4 is full privileges. If she refuses to do something after two prompts, drop her a level and take a privilege away. If she keeps going keep dropping her a level and take away another privilege. Level 0 is grounded to bedroom with no privileges at all and she has to earn checkmarks in the day to move up a level.

I have a step son who has a mild form of autism and he was very prone to violent aggressive behaviors when I first came here. Five years later, he is better with the behaviors but has trouble listening to me once in awhile.

Whatever you decide to do, talk to oyur husband first and then have a family meeting and let the children know what you are going to do.

Hope this helps.