Re: French playgroup/summer camp for a 3 year old (GE, VD)
Three years old is much too young for any summer camp that I know of. You could probably find a play group but that means parental presence, and many may not meet up during the summer holidays when everyone is typically away. A creche or daycare may be possible but are you really only looking for 2 months? , then that too will be difficult.
If you speak french, look at the website Vaud famille, as it is a good resource for all things childcare related in VD.