Thank you for so many replies! Its really helped me.
I suppose I wasn't ready to reside myself to the fact that I might have a 'MIL from hell'
I definitely get the feeling that she sees me as the person who 'stole' her son, there have been quite a few examples but one of the most prominent was just before we both left our parents houses to move into our own place. She got upset because she wanted 'one last family holiday with the boys' to New York. Dh laughed and said he's 24 and wouldn't have gone anyway, she got upset and blamed me- even though it was her son who said it to her! That grated on me alot, I know I must seem like I forgive alot but some things she has done have deeply hurt me.
I just hoped we could maybe draw a line in the sand, and she would stop all this manipulation and mistrust, since we are having a baby.
I really don't want the snide remarks about me to extend past when the baby arrives, at the moment I just know she is going to try and take over, then when dh gets annoyed and they argue- ill be the poisonous DIL... Its the same every time.
Also, I don't know if I will have the patience for it when our child comes into the equation, ive handled pregnancy really well and feel very self sufficient, if she starts with her usual 'concern' over the way I'm going things, it may cause an argument between us.