Interfering mother in law?

My mother in law and I have a very testy relationship to say the least. We have not got on much at all and clash a lot. We both have very strong personalities and our own opinions on things. We have had many arguements and fall outs in the past because she is very controlling, demanding and wants her own way all the time and the family let her have it but I don't and she doesn't like it. I do try and be respectful but they is only so much allowed. Well I am expecting baby number 2 and I just know she is planning on taking over and trying to tell me what to do. Hubby will take her side and say she is just helping because he never sees wrong in her but I don't want her interfering unless I ask for her help which I won't. Her daughter had a son 3 years ago and she let her take full co tell and she thinks I'll do the same but it's not happening.