Mother in law

Marissa
So my mother in law doesnt have any interest in me, or her soon to be born grandson. I've been married to her son for one year, and together for two years, and his mom does not even know how old I am. She does have other children though who have kids and she shows great interest in them. She also has a somewhat relationship with my husband's ex wife and the son they have together. My MIL has not really asked about my pregnancy or how I am doing and never calls or texts back. Very seldemly at least. She is always nice when I see her but never really gets personal with me about anything. My question is, when do you get to the point of giving up on trying to have a relationship with someone like this? My son will be born in 6 weeks and I cannot figure out how I will allow her to be around, if she decides to be around, without having a lot of resentment towards her. Any suggestions or opinions would be greatly appreciated.