It didn't occur to me at the time, but I'll come clean - yes it was an Advance. From Lime Street to Euston, with the first leg being on London Midland. The reason for changing it was that there was only 10 minutes connection time allowed at Crewe, to change between Platforms 5 and 6, so up the stairs and over the bridge, or wait for the slowwww lift.
My friend had a medium sized case, and a backpack, and is, ahem, my age (for those who have met me
), and was unfamiliar with Crewe station so getting herself into a bit of a panic about making the connection.
She already had a Saveaway which meant she could get to Chester "free", so it seemed like a great idea to start her journey to London from there.
She probably broke all sorts of rules by omitting the LM leg, although she was covered by tickets for her whole journey.
It's ironic that at Crewe when I would like a 5-minute connection allocated, I get half an hour, and when someone would appreciate a bit longer they cop for the 10 minute minimum.
Anyway thanks everyone, and I understand now why we got the response we did.