my cousin who is visiting London from Australia for 2 weeks is staying near South quay Station. I have one day to go up to visit her with my 2 and 5 year old from Sevenoaks (SE). I want to spend fun lovely day with her and she is childless 20 something. What could I do pleasant for everybody without too much stress? Docklands Museum is unfortunately shut and It's supposed to rain this Tuesday when I'm going...:(( HELP!!