Quiet places to visit in December with autistic DD?

[AutumnBeast]

Hi everyone, I’m looking for somewhere to take DD (16) for a few days in early December. We both love the sea, visiting atmospheric towns with unusual shops but neither of us can cope with crowds. Any recommendations for somewhere that might be a little quieter but where we can still do a bit of Christmas shopping? South coast or south wales easiest to get to (but could go further afield). Thank you 🙏

Looe and Polperro in Cornwall

Thanks @Forgottenmyphone will take a look

Looe was the dullest most life sucking place I've ever been to and that was the height of summer (sorry to those that live there!) It wasn't spooky as such but it certainly had an odd vibe and I was thrilled to be going home after a week staying there.
The first places that popped into my head were the little Yorkshire towns, not the touristy ones like Haworth or Skipton as although amazing they might not be quiet enough. Might be too much of a trekk for you though OP?

We could go a bit further afield if it’s the right place but we’d probably have to stay an extra night. Really welcome any recommendations to be honest. I’d love to take her to Whitby some time. What about Totnes in Devon?

Whitby!