Brace yourselves, it's going to be a long one... I hope this is an acceptable question here; if not I wonder if the Interpersonal Skills board might take it?
TL;DR: My 14-year old daughter wants to visit a young man I've never met who lives a significant distance from us. I'm reasonably confident it's safe because of context, but I want to know how I can be more certain.
I'm a single mother with a 14-year old daughter, who we'll call Lydia. A few years ago (think when Lydia was 11-12), we had an older (17-18) female friend (call her Ella) who she'd met at school babysit for her after school while I was still at work. Ella became a good friend to Lydia, and I trust her (Ella).
I assume they hung out together at school as well, as over the summer holidays 2016, Lydia started mentioning some of Ella's friends in idle conversation. Fast forward slightly: she started talking to one of these friends (Ella's age, and we'll call him Oliver) on Facebook. They've met in person a few times, both with and without Ella present, so I'm confident that at least he's a real person who is who he claims to be.
For better or worse, Ella dropped out of our lives when she left school and went to university. Oliver didn't (drop out of our lives that is) - Lydia continued talking to him online and they have a good friendship. Lydia is having a number of mental health issues that she won't talk to me about (I think I've reacted the wrong way to them previously so she won't trust me with them any more, but that's another issue), but she talks to Oliver about them and says he's really helped her.
The current situation: Oliver is at university around 100 miles away from us ("us" being in London). Recently, Lydia brought up to me the idea of going to see him for a day or potentially a weekend. I hope some other parents on this board can see why I'm nervous about that.
I would like to be able to allow her to go, because I think it would help her and make her happier, but I'm still not entirely without concern. The journey itself is not a concern: it's not a difficult trip by train, I could take her to the station one end and Oliver could pick her up at the other. However, while I'm reasonably sure that Oliver is who he claims to be and Lydia would be safe, I've never personally met him, which makes me nervous.
How can I talk to Lydia about this? What can I do to allay my own fears? Going with her is out of the question - she would rather not go than have me with her. What other options are there?