Good grief ! talk about them stepping way outta line.. Who knows what the cause of it is.. Looney for sure..

Could it be a control issues albeit stupid !
Can she have a talk with them to find out why in the hell she cant have some time to visit with friends?
If that doesnt help matters I would personally just find a new place to meet up and not tell anyone where it is. Seems stupid to be a grown up and sneak around .. but maybe that is the only way she can catch a break.