Always interesting to read how LWs describe family.  Sometimes issues with "boundaries" and "control" are nothing more than noting you have screwed up in the past & depended on family to pick up the pieces.  I don't know that this is the case, but the rest of the letter hints at someone who doesn't always think things through.  

First, she can't seem to tell her mother that she's moving even though she's made the decision.  What does that say? Grow up, be truthful with your mother. Arrange for her to get a passport for Christmas so she can visit you. If you don't want her around, make sure SOMEONE in your family has a passport, because one serious accident & you will want someone to come. Make contingency plans for if you can't work & your boyfriend has second thoughts.  Explaining your move & how you have considered & prepared for the worst could make all the difference in your mother's attitude.