I think the only thing about giving the address at a time of reassurance that it won't all kick off, is that when the aggrieved party gets wound up about something else, they will be off like a shot to have a go at her and things will worsen. If your daughter asks you directly for her address, then perhaps you shoud give it to her with reservation, and say you expect that information to be dealt with responsibly - after all, they are complaining of the other daughter's lack of responsibility. I certainly wouldn't offer it, though - it might give an implicit signal that you condone them going round to have a go, and the erring daughter will be annoyed with you for offering it.