text: what do you do when your sister-in-law keeps causing problems? my  sister-in-law was so nice to me at first and then just turned nasty, she has caused several family problems, i think my brother-in-law is a fantastic person, but he isn't allowed to visit us anymore and i feel bad for my husband who now seldom see's his brother. she can't seem to get along with anyone, even her own children and siblings. the problem is that her and my brother-in-law got married only after knowing each other 2 months and as soon as they were married she gained 50 lbs and turned into a different person, a nasty one. i have tried to pretend everything is ok and gone to visit with my husband, but she just sits and watches tv and won't even look at us. she is mean and rude and i feel sorry for my brother-in-law because i think he feels stuck in the relationship and won't say how he feels.  do we just keep ignoring the problem and let her go on hurting everyone around her?? i have had almost the same problem except it was my own brother. his wife was a bitch on wheels. rude and unsociable to anyone. we tried to be nice, invited her on vacations you name it. we even tried to talk to my brother about the way she was but he didn't want to hear it, even though he knew we were right. after being married for 7 years he came to his senses and divorced her. yeah! it was a great day. so my advice to you is, let him be for now. he will come to his senses; hopefully in less than 7 years. its better to let him figure it out on his own then lose a brother over an argument about it.