Yes exactly! With only two solid facts about your Cinderella (1. They work in the service industry, 2. They wear a size 5.5 crystal shoe), you’re never realistically going to find them. Especially if they’re in their work clothes with their work personality on. So there’s really only one option left.
Go round every local coffee shop, burger joint and hotel and get all the staff to try on your weird tiny shoe.
Your description kind of made me think of Miegakure. Though it’s not about time, it is a 3D platformer where you have to move your 3D reality through a 4th spatial dimension to uncover the puzzle.
Really looking forward to playing it when it comes out.