This happens to US parents also, boyfriend comes between daughter and loving parents. Can you do anything legally? No, as you said she is an adult and you certainly don't want to have her declared mentally incompetent.
She is having a delayed teenage rebellion, mine came at 14. Although she acts passive she really has all the power in this situation (assuming her BF does not control her 100%).
Cutting her off financially (car insurance, phone) is called "tough love" but I agree keeping her on your health insurance is wise. Tell her you will be there for her if she wants to visit. Can you get her siblings to call her once a week and keep communication
open? Maybe have them give her a pre-paid cellphone so she can keep in touch with them. If BF is controlling her he WANTS to cut off communication with her family.
You already know her BF lies to you but do not criticize him when you talk to her (he wants you to so don't). Just talk about
what SHE is doing. Tell her you love her and want her to be happy. Invite both of them to dinner at a restaurant with your other children (not your home). Try and make it drama-free. Talk about
what your children's plans are in the next month. Talk about
a vacation and invite BF to come (if it's not too expensive). Sometimes teenagers want negative attention just to stand out from everyone else.
Welcome to young adulthood US-style. Some kids are easier than others.
edit to add: your descript
ion of her as "homely" may be honest but it means anyone outside her family who shows her attention will attract her to them. Not saying the BF is a predator but that's who seeks out low self-esteem females and then uses them (and the girls accept it because the BF "loves" them). Again the BF may actually like her and not be a predator, in which case could become your SIL. In fact why not talk about
wedding plans, that could make him run away fast haha.
Post Edited (imagardener2) : 7/13/2015 12:07:30 PM (GMT-6)