kids constintly fighting
I have a 7 year old daughter that was mine from a previous relationship and my husband has a 11 year old daughter from his first marriage.. every time his daughter comes over to our house shes fine for a while but now that my daughter calls him dad she seems to have a attitude, i can here his daughter picking on my daughter telling her to do things she knows she is not spose to do, and when i mention it to my husband we have a fight. I am at ends with it and his daughter told me just because your with my dad doesn't mean i have to call you mom which i never asked her to do so, i need help with this
What a hard situation for all involved. The girls aren't getting along which is causing you and your husband not to get along. The 11 year old is resentful of you and your daughter and she's definitely letting you both know.
So… what's a mother to do? The first thing I would try is to see if you and your husband can put together some "household rules" and come to an agreement on discipline. Once the two of you are on the same page, it will be MUCH easier for the girls to adjust. They already know what they can get away with, but if you take control and don't let them get away with as much they will respect that and you will see attitudes change.
This is different than running to your husband because "his daughter" did something to "your daughter" (or told her to do something that's not her responsibility). Don't pin him against you by using his daughter. That simply won't work. But rather, leave his daughter out of it, and start with your daughter. What can we do together to help "my daughter". Once he feels like the two of you are on the same page with her, then he will be much more open to working on "his daughter". I gave you some suggestions on how to work with your daughter here.
And if your husband simply doesn't want to discuss "his daughter" then you will need to pay constant attention to what is happening between the two girls, and you will monitor things. This is going to take a lot of your time, but it can be done. Have the 11 year old bake cookies with you. Have her help you with the cooking, have her go to the grocery store with you, while your husband stays home with the 1 and 7 year olds. You'll want to develop that relationship as if it's more of a friendship simply because she is showing signs of resentment at this time ("I don't have to call you mom.").
You can control the situation better. You can plan out exactly what each girl will do after school so they aren't having any "alone" time. You can play a game with them, do their homework with them, have one in one room doing something while the other is in another room. Once the resentment wains and the relationships blossom then you won't have to spend as much time watching over everything. But for now, resentment often times accompanies the mixing of two different families and it can be easier to work on a friendship before becoming a "parent". My mum died when I was 16, and my dad remarried a year later. It was REALLY hard for me to accept her. I was dealing with the grief of losing my mum (your step-daughter is dealing with the grief of losing her family due to the split). I found it was easier for me to take direction from my dad (i.e. clean the kitchen) then it was to take that direction from my step-mother.
I wish you all the best on this one. It can be tough, but I know that with some work you'll be able to make the transition and everyone will become happier.