Why is future mother-in-law so upset that I want to do all the wedding activities with just my mom?

Word through the in-law gvine is that she is mad that I prefer to do all the bridal and planning stuff with my mom. Duh! She is my mom! FMIL's daughter married 2 years ago-I know she loved that time with her daughter and she understand why I want all that precious time with my mom. Why can't she allow me the same courtesy and not intrude? It just seems petty on her part and is only pushing me farther from her and reinforcing my negative impression of her.