Hi Yoko
The following might be useful, my two year old son and I (and plenty of English speaking mums) attend on a regular basis
La Maisonnee is in Morges, opposite the Casino restaurant and the
Vallee de la Jeunesse is just before the Maladiere roundabout as you head into Ouchy so both are very quick from Morges.
http://www.espace-prevention.ch/oues...onn%C3%A9e.pdf http://www.valleedelajeunesse.ch/
Both are free playgroups, the opening hours are on the websites. The ladies who run them usually speak good English and I have to say I've always found it easier to make English speaking friends at the Swiss run playgroups than I have anywhere else.
Personally I found the moms in vaud group tended to meet up towards Nyon/Coppet area so that didn't work for us. We've also been to Edukids a few times for a music group but I think my son was too young at the time. I believe they have a coffee morning every month though, which I keep meaning to go to!
Happy to meet up/answer any questions if you would like more info - just PM me :-)