Mother in law madness

Okay here’s a little back story I’ve been with my husband since we were 13 years old were 30 now married and 6 kids later . My husband and I just recently moved to Washington to be closer to his family were from Florida and we just wanted a new start somewhere else okay fine perfect. Mind you guys I never really been around his family except his dad and brothers because his mother moved back to Washington when he was only 14 so she will she come down to Florida to visit at times but long story short I just know this lady don’t like me she puts on acts in front of my husband like she does but she can’t even hold a conversation with me mind u I’ve been with her son 15 years and I have 6 of her grandchildren that she really doesn’t care for in my opinion she just acts really weird with my kids my 15 year old also says the same thing I always tell my husband I don’t wanna go over to her house because I feel like she doesn’t like me so why be around her it makes no sense but he takes it as I’m being childish in a sense I guess so now tomorrow is her birthday and he wants me to call and order a cake for her mind you she has 2 other kids that never buys anything for her birthday and we do it every year I’m just starting to feel like their using us every time their borrowing money and never pay back I’m just over it any advice lady’s please help me out