After mentioning it here in mn (ages ago!), I've finally created a writers' group for mums in London, in Meetup:
www.meetup.com/London-writing-mums/
The plan is to arrange meetings in places/times that are baby/child friendly, discuss writing, critique each others work, etc. And maybe even invite writers to talk, or arrange to go together in events and book launches.
If you're interested, please join! I'll organize a first meeting as soon as there is some people in the group. Suggestions of days and venues are welcome.
Thanks in advance!