You probably should not bother advising her. If she says she plans a trip to the Carribean at the height of hurricaine season, or a trip to the Midwest right when tornados are predicted, just say that you hope she has a good time. It'll be what it'll be, and whatever that is won't really be your problem.

I don't think I would distance myself, necessarily, but I'ld lessen the time I spend on these daily phone calls. It's not selfish at all to burn out on listening to someone whining. You don't have to announce your intention to her. Just do it.