Don't know what to do

Hi,

My MIL came to visit us for 15 days. In the meantime I was diagnosed with sciatica and I can't even walk more than a few steps now. Due to this my FIL decided that my MIL should stay with us till my delivery date(due in Dec). DH also agrees with him. Now she is little helpful but not as much as I need right now. She watches tv and sleeps all day. In the time that she is awake she asks me if I need something. I am not very comfortable with her and this whole idea of living with in laws. But at the same time I cannot express my displeasure since my mom and dad will be here a month before my delivery, and I don't want DH thinking that I have an issue with only his family. However whenever my mom is here she takes care of everything including groceries. Ideally, I think I should not have a problem with MIL living here but I don't want her to. This is driving me into depression day by day. Small things about her irritate me. She is a vegan and nit picks a lot. But DH handles all that. I just don't know what to do.