Massachusetts - finding other toddler parents

Hi,

Out toddler is 2 1/2 and had been in day care since age 1. Now her
baby sister has arrived, mom is staying at home and she is no longer
going to daycare - and appears to be missing it a lot - the structure
but more importantly the interaction with other kids.

What are the resources we can use to perhaps locate other moms of 2-3
year olds who are up to meet 4 days a week or so at a consistent time
so kids can play and socialize?

So far the library/park is great but not consistent with who is there
etc.

Perhaps there are toddler mommy groups somewhere? Ideally in the
Walpole/Canton/Norwood area south Boston.

thanks!

Tim