Monster in law

Victoria
So my mother inlaw has always played favorites between my kids (I have 2 daughters ) my older daughter is 5 and my younger daughter is 2 every year she helps me with school shopping rich I do appreciate very much but she is always asking if she can take just my older daughter and it bugs me a lot well 2 days ago she text me asking if she could take my older daughter for school shopping I said it was no problem but I wanted to go with because she doesn't pick out very cute stuff she then caught a attitude and said I was ungrateful I told her that its not true I would just like to have a day in what my daughter is getting for school she then basically said that she didn't want me to go because then my younger daughter would have to go and it would be craziness well need less to say I flipped I told her that she is done playing favorites Natalie (my younger daughter) is old enough that she wants a part in stuff too so yesterday she called my husband and was talking crap about me and told him everything I said to her to make me look like the bad guy and my husband didn't say a word I got so mad that he just let her talk about me like that and didn't say anything so now I'm between should I call her and confront her or should I just let it blow over and be done with it sorry it is so long I just had to vent