Pictures with step daughter pop

Okay y’all so I need some help. I feel pissed off about this situation, it could be because I’m pregnant or it could be I’m over reacting. I have a step daughter who comes over every weekend and hardly ever stays with us she is always at her Annie’s house(my husbands mom) that is another story in its self. My mom wanted pictures of the girls done I have two and she paid for it, I didn’t. So I took Christmas tree pictures with my girls, now my mother in law and sister in law are pissed that my step daughter wasn’t in them. 1.she was in NC with her aunt an nobody told me until we was getting ready and I’m not canceling pictures last minute. 2.they are mad she didn’t even have a matching outfit, I told them no I didn’t buy her one because I’ve bought her many and she never wears them so I’m not wasting my money. 3. They leave my two children out of everything and only take my step daughter and my sister in laws son to do anything,whatever tho I don’t make a big deal. 4. They don’t act like she’s my step daughter at all but if I do something with my kids they feel she should be involved. I don’t feel like I was wrong for taking pictures with my girls and I won’t be made feel guilty for it even tho they keep saying I wonder how Victoria will feel being left out of pictures. Do you guys think I’m overreacting or do you think I have a right to be upset with the way they are acting over this?