H, I don't think the airline would be allowed to do that. And to be honest, other passengers would still all be strangers to me (and her) so wouldn't really fancy that! She will be fine to fly by herself on a daytime flight (I would prefer that she wasn't in Dalaman airport alone late at night/early hours when she would be very tired and more vulnerable), and will be met at the arrival airport by a family member. She will probably read or listen to music for the entire journey - I wouldn't want to ask a complete stranger to take care of her, making her feel that she has to make small talk with someone she doesn't know.
However, if there is a cbf member travelling back to Cardiff or Bristol mid August who doesn't mind a 17 year old tagging along with them, please message me!!! (Most would still be strangers of course, but I would feel a bit happier with this arrangement!)
Thanks for your message Ron - great to hear from you. Will try those numbers tomorrow as I'll have more time, and then reply to your email. x