DD (18) is asking if her friend can stay with us "just for a couple of days" as she is having fierce arguments with her mother. DD has been friends with her since they were at primary school but really, the friendship has always seemed be more valued by DD than her friend they often don't see each other for ages.
I don't mind her staying literally for two days but much beyond that and it becomes quite difficult for us to continue with our usual lives and take her into account (meals, work, going out etc). Her friend was at college but has dropped out of her course and would be hanging around the house when we are all out (college, school and work).
I am a bit worried that DD is not thinking this through and she is implying we would be horrible people not to invite her poor friend to stay with us as she "has nowhere else to go". I do feel sorry for her but I think there is probably more to the arguments than meets the eye and of course DD will be getting her friend's perspective only. I don't want to be unsympathetic and my instinct is to say yes but only for two days, strictly. Would this be reasonable?