Christmas activities in London

[Yummybumble]

I’m looking to take two small children to London to see the Christmas lights. They’ve been asking to see where mummy works so I thought it would be a nice reason to go.
What are the best things to do, boy and girl 5 and 2. Think free/cheap things to do or places to visit. Nothing too formal!

Not specifically Christmassy, although I'm sure they will have decorations, the children's museum only re-opened this year after major refurbs. Its free and on the central line.
I haven't been since the refub, but it used to have lots of interactive toys. Interesting for adults too.
Young V&A (vam.ac.uk)

I find Museum Mum on Twitter and Instagram really helpful for lovely things to do with kids.
https://museummum.com/free-christmas-london/

Regent Street lights are beautiful