Isn't she an "EX" girlfriend? Why would she want to keep living with an "EX" boyfriend? Anyhow, did she sign a rental or lease agreement with one of the owners? Typically when a home is sold, it has to be free of all personal belongings as well as tenants. If she has no agreement, I don't see how she can be anything more than a trespasser after the property is sold. However, in Massachusetts, she is probably protected. I would consult a good real estate atty in the area. They can give you the answers in 15 minutes.