I spoke to Elegant Lady this week
Actually, I really inconvenienced her but no need to dwell on that. I put her things in the nicest bag we had to make up for it, it did not go unnoticed.
So what did I learn? She just looks "on the off chance". She sticks to neutrals for shoes (mainly) trousers and coats/jackets. She does use colour but limits it per outfit and always accessorises. They can be statement pieces but they coordinate with one or more items she's already wearing.