Not sure if this is allowed or not but seeing as there is nothing listed here for kids and there is so much actually going on in Balham for families, I thought I'd share a link to a website I've found that seems to have a really comprehensive list of everything going on for mums, babies, children and families:

http://tinyurl.com/6ccsxzw

See what you think. I've definitely found a few things I didn't know about that I'll be trying out with my kids!