I've just heard about this place in Beckenham (Penge-ish border) at Venue 28 (the beautiful old building next to the Beckenham Spa Pool. It looks interesting.
http://splattermake.co.uk/
Here is the blurb:
"Splatter Make aims to bring children, young people, parents and those with a passion to learn, together. Splatter Make has established a thriving community of people who are learning skills once traditionally passed down in the home or in schools whether it’s hanging wallpaper, altering clothes or making jam according to the seasons."
They also have loads of ideas on their Pinterest page for little 'uns (we use pinterest a lot of ideas).
https://www.pinterest.com/splattermake/
It looks really good on the website. They do workshops and classes in the Easter Holidays.