Again - you are trying to control how your W or her family view you. And quite frankly I bet they view you as a wimp.
Do you see a pattern here? When your MIL doesn't get her way she either manipulates the situation until she does or she stomps her feet and makes enough noise until people just give in.
Your W does the same thing.
And when your daughters pitch fits (which you have posted about) they are doing the same thing.