Yes, hurray for the job!! I wish I could tell you more of what to do with your MIL. I used to get along very well with mine until about a year and a half ago we had a ugly fight. She wouldn't talk to me after so I apologized through FIL but either she didn't want to hear it or even never told her. I felt she should apologize too but I guess she isn't big enough to do that. Better off now anyway that they invite his gf to "family" events.
Give it time with BF. Try to address things as they come up so that the resentment doesn't build. Time is what this is going to take.
You are doing so good! Hugs, kat
Me-53(and learning!) S24, S21, D18, D17 Just keep swimming, Just keep swimming. Dory