I've been dating my bf for over a year now and 6 months and we are planning on getting married next year. But his six year old daughter drives me up a wall, and I swear she does it on purpose and knows what she's doing to get to me. I have a 9 year old son, at times they get along great but if other kids are around she has to be in charge of everything and bullies the other childern. My sisters daughter who is the same age as my bf kid doesn't like playing with her anymore, because they were in the toy room the other day and the step daughter wanted my sisters kid to play with her more, and she didn't want to, so my soon to be stepdaughter twisted my nieces finger. She ran out of the room crying told my mother and me what happened her hand was clearly red. But I asked the devil child why she did it, and her words were that my sisters daughters kid is a lair and that she didn't do it, then she rolled her eyes at me. When her dad got off work I told him what happened all he said was his daughter is not the only one to blame. He doesn't discipline her, he will yell but she will go right back doing what she wasn't suppose to be doing in the first place. Also I have watched her a few times for my bf and she is really bad, she has told me I'm too old to be with her dad, I'm 29 her dad is 26. I tried explaining this to her about age and she didn't even listen and her dad was right there. Another time my sister walked into the toy room to find the devil child slamming my sons toys up against the wall, she told her to stop! And the reason why she said she was doing it was so she could break them. What kid acts like this? I don't feel this is normal behavior for a 6 year. I've tried to sit her father down and talk to him about it but all he's told me. That his daughter wouldn't do anything like that and she is not the devil and that my sister is lieing, now why in gods green earth would my 27 year old sister lie about a 6 year old. It is at the point where I'm not sure if this relationship is for me, because she doesn't listen to me. Even my bf mother said to me that she has a hard time with her. I feel I can't take it. We have a vacation in less then five days we went halfies on a condo, I'm hoping the little girl wont have any behaviors while we are down their. My bf and me get along we'll except for his parenting style and when I've tried to discuss it with him he gets angry with me and has a huge blow out. So mentally I've just thrown my hands in the air with it all, because its not my kid and I can only controll so much. I don't feel it is normal for a 6 year old to lie as much as she does, she has made up stories about me, that since I wouldn't let her play on the tread mill she was going to tell her dad and I'm meen to her and don't let her do anything but I'm sorry the tread mill is not a toy. She cried for and hour and a half on the couch, and all I did was tell her no. Any advice or stories anyone would like to share would greatly appreciate it.