Would you expect them to? Would they be happy to do it or very nervous?
16 year old SIL is coming to visit for the weekend, MIL is driving her down. On the way back the train journey requires one train into London, one stop on the tube, and one train out of London again. Tickets aren't booked yet but they would allow about 45 minutes to make the change from one mainline train to the other.
MIL is saying that one of us has to go into London with SIL and put her on the last train. Is she being overprotective of her last baby? Or is this normal? What would your 16 (or 15, or 17, or similar) year old make of it?
(Obviously if SIL says she does want escorting I will go with her, but letting her make all the decisions, so she is not just following me but figuring out how to navigate the tube on her own)