We have found some free/interesting things to do over the Easter Break.
Free events at the Southbank Centre. Southbank Centre Free Events
London transport museum does £1 annual passes for families on Universal Credit (and have a great play area for little ones). London Transport Museum Information
You could also visit Mudchute Farm, Maryon Wilson Park, or your local Children's Centre Children's Centres Near Me | See All Locations by Area | Better