The singing and signing is at the Lido I think (if you mean the organised sessions through Sing and Sign).
The Friday morning baby session is very good. a bit more organised than the afternoon free for all, with singing and the like.
I hear that the One o'clock club is also opening during the mornings too.
Plus Saturday mornings for Dad's too!
You might also like Efra Parade toddler group on Tuesday and Wednesday 0930 start but get there EARLY.
Or Corpus Christi on Brixton Hill has a baby/toddler group on Wednesday and Friday 0945 - 1145.
In the park I'm the dad pushing the hyperactive boy waving at all the squirrels, ducks, dogs, people and any passing plane. Come over and say hello...
If you'd like to arrange a coffee in the park I'd be happy to join you.
Thomsc