Hi, my husband and I got married about five years ago. When we were seriously dating his daughter who is now 14 years old would stay every other weekend.
Her behaviour wasn't great in that she would talk about me in third person to my husband when I was in the room eg "how long has she lived here for" etc and my husband did nothing about it. It got so bad that I calmly spoke to her and said that it wasn't kind to ignore people. From that day on she has refused to come to our house.
My mother in law also plays games of being favourite so rubs our faces in it and hints to my husband that all of this is my fault because her granddaughter said that I'm really horrible to her etc etc. Basically lots of games go on.
Not sure what to do as now we have a three year old son and he doesn't have a clue who she is!