Best small town in the peaks to visit for my mobility-challenged 76-year-old mum.

Hi! I hope this is okay to post here. My Danish mum is coming to visit me in a few weeks, and she wants to visit one of the small towns in the Peaks. She really just wants a very English/Northern experience, have a nice pint in a cosy pub and the like.

She can walk fine, but struggles with elevation. So it's mostly about staying in a small town for the day, and head back to Sheffield towards evening.

I don't drive, so it needs to be reachable with trains or busses.

Any suggestions?