Lets meet at parc Montsouris (in the 14th), take a walk around the beautiful park, and let the kiddos play in the playground (and let the babies get some air).
Bring baby's lunch and a blanket for the grass if you can! If the crepe stand is open (it's open on sunny days now!) we can grab a bite to eat and feed the kids there.
If you're new, the meeting point is the entrance nearest the Cité Universitaire RER station.