Hi mggt,
My dd18 has done the same in the past... . either given me the wrong info and half of it missing especially if b/f is involved somehow. It makes me wonder if they think we will really turn up to spy on them or something.
Iam now a new grandma and I dont think i would have handled it any differently from you., It just makes sense to know these details incase of emergencies.
I find that the more I press any issue the less likely my dd is to see sense sometimes, so if it were me I wouldnt say anymore on this matter. Also dont worry what she says b/f says either. My dd will often do the same. Says so and so said this and that to back her behaviour up when it isnt actually so.
Hopefully your dd will leave you some contact details but if not try to keep yourself busy and try not to dwell on things.If you do get the chance to speak to her before she leaves just Keep it upbeat and wish her a good vacation.
While she is away you could look at putting some boundries in place especially around the tone of language she is using with you.
It is unacceptable to be spoken to in that way mental illness or not