Step daughter's behavior is not improving?

she has been living with me and her dad (my husband) for 5 months on and off.....not 100% of the time because she goes to visit her biological mother...Long story short, she is 5 years old, and everything we teach her goes through one ear and out the other. B4 you guys be judgemental, please hear me out. I have plenty nieces and nephews and my own child and I'm really good with kids. I AM IN NO WAY SHAPE OR FORM JEALOUS THAT MY HUSBAND HAS A DAUGHTER THAT IS NOT MY CHILD. for 5 months, we tell her to wipe herself after she uses the restroom and she wont. we tell her to stop snaching toys and being mean to her toddler little sibling,....we tell her to stop telling lies....stop being so so so obnoxiously LOUD ALL THE TIME.....stop taking her clothes off in the livingroom and dumping them in the middle of the floor and leaving them there...stop being mischievous & conniving and trying to hurt her toddler sibling when our backs are turned.....i mean everything we teach her she does not and has not improved on AT ALL. every other kid she gets around, she influences them to do bad things and they end up getting in trouble. every daycare provider we take her to has to put her in timeout often....I told my husband I prefer her to not call me mommy because she calls random women mommy to get what she wants...but when she's around her biological mother, she calls me by my name. so now she tries to tell ppl she cant call me mommy and it makes me look bad. I feel no sincerity from this little girl at all. almost everything that comes otu of her mouth is a lie, and she tries to butter me up by saying "mommy, i love u so so so much...can i have some ice cream?".....she hasnt even known me long enough to even be doing this. i feel uncomfortable and I dont like her behavior. she is very VERY disobedient...we tell her to sit down and be quiet, and 30 sec later she is up jumping around and making her sibling cry...we cant even watch a movie! she disrupts everything. at night, she gets up constantly doing random things like running the water in the bathroom sink or clapping to wake up her little sibling. when she is gone, our home is SO SO SO peaceful. when she arrives, all Hell breaks loose. she annoys everyone that is around her. she will grab any random person's phone and start pressing buttons and doing things she shouldnt do. she lied on the daycare provider saying she hit her, when she actually only put her in timeout. this scares me...when she starts school soon, i worry she will say something like that about us and maybe get her and my baby taken from us! i dont know what to do. i dont want to leave my hubby and i told him i would be there to support him, but neither of us knew she was gonna be like this. he just met her for the 1st time recently too. Again, i do nice things for her and take her places and try the punishment/reward system and nothing is working. any suggestions? this little girl is driving me bonkers and i am getting at my wits end. i dont even have any 1 on 1 time with my baby when she's around b/c she tries to mimic what i do and crowds our space when im holding my baby...she hides food in our car under our seats and makes things dirty....she is very very jealous and does not want my husband to show me or the baby any sort of attention....and, she talks to random strangers and runs from us in public places. she tells random ppl our personal business and has embarrassed us plenty of times. when we chastise her and tell her to be quiet or tell her she's in trouble and go to time out....she retaliates by writing on our furniture. I have been praying so so hard and even took her to church with me. I dont know what to do.