DD has a friend Jane who is 17yrs and will be 18yrs in the summer hols. A few months ago Jane went on a trip by herself abroad (I'm going to ignore the Covid implications as that isn't the point). While she was there she was having one night stands, going back to the flats of men she met on nights out - stuff dd described to me as 'risky' behaviour, I suspect we are not hearing the full extent of things. Dd is not remotely judgey or prudish and usually doesn't tell us any of this stuff but has mentioned it to me and dh separately so I think she is worried.
Now Jane's parents are funding another solo trip abroad (again, consider
x 10000000 re. Covid implications) in the summer holidays.
I have no idea if this friend's parents know what she is up to on these breaks but they are delighted with how she has 'caught the travel bug' etc. I don't know the parents but do have contact details (from party pick up arrangements a while ago).
So AIBU to just step back and let this girl get on with putting herself in these situations. She's almost an adult and it's really up to her and none of my business. Her parents either know and don't mind or have no idea. I don't want to betray dd's confidence but there's a part of me that thinks if my dd was doing this, I would hope someone would tell me! I remember a poster on here saying her parents were super liberal and she got up to all sorts of stuff she wasn't equipped to deal with and she wishes her parents had set some rules, that has always stuck with me. Jane is a bit of a drama queen and dd says there is some talk about Jane being autistic (from Jane but other friends think it is likely) but she has no diagnosis. I've met Jane several times and she has no filter. She's actually quite charming but I think quite vulnerable in a way, not so much wears her heart on her sleeve as just hands it over to you straight away IYKWIM.
YANBU - just keep my nose out of it
YABU - say something to the parents (not directly but in a way which protects dd as being the source of this information for example through a third party)