Ex Wife Threatening Court

Hello,

Need some advice. Currently engaged and buying a home with my fiance. She has moved in with me for the short 3 weeks left until we close. My Ex who took me to court earlier this year for my fiance staying in my home when my 10 year old daughter is with me although she was in her own bedroom and we NEVER slept together when she was with us. The court allowed my fiance to stay. Now she is threatening to take me to court again because my fiance's son who is 22 is staying with us as he has new job and we are only 15 minutes from where he works. Before he had to drive an 1 hour and 15 minutes. It may be some time before he finds a friend who can be a roommate and he can live on his own. He is a great kid who just does not make enough money to live on his own. Does she have a case this time? Any advise?