While many people have been in your shoes, few seem to have worked it amicably.
My suggestion is to
1. Sit down and talk with hubby about it. First ask him what he thinks about the situation and how he feels. Then ask him if he has any suggestions on how to mend things. Hear him out first. He is the one caught in the middle.
2. Then you can make a list of his suggestions.
3. Air your side of it in as unemotional (no crying or yelling) way as possible. Men really like to hear the logical side of things and talk calmly.
4. Make your suggestions on how to solve the problem and add those to the list.
5. Go through the list together and decide in order of what to try first. Try to come up with at least 3 things you can do together to work on this problem.
6. Implement the plan.
[ My suggestions are- wife talks to MIL and asks her what specifically the mil finds offensive about the wife, her wifely duties, and her mothering duties. Have pen and paper ready where she can see it. ;-) . Then see if you can work on one thing and if she is willing to talk and work on things on her end.
If that does not work, then I suggest the hubby talk to his mother and say the same things. But in the process he needs to make it clear to his mom that he married you and not your clone. He needs to make it clear that he does not need her approval for his families way of doing things.]
Finally when MIl is in your home, your house rules apply no matter what. Kids may stay up to visit but they still brush their teeth, don't drink soda, or whatever you rules you have in place.
When in her house, her rules apply except regarding the safety and health of your child. Compromise and let little things roll off your back.
For instance my MIL would feed the kids left over fried chicken for lunch and although dd did not like it, I told her to eat what was served. But I did reheat it for them and she sneered at that, but I told her I personally don't like cold chicken and do not mind heating it for them. I did not make an issue of it and she did not either, although she did make her feelings known. I don't care if she does that. You have to have tough skin. ;-) She is not hitting on my parenting skills, just saying I am spoiling my kids a bit much, which is just fine if she wants to think that. LOL