[Highland Park] Activities for Mothers and Children?

Last week I received the following inquiry:

Hi, I moved to highland park about 3 years ago. I have 3 children, all boys and ages are 6, 4, and 2. I was wondering if there was any activites for them? I am trying to find groups and fun things for them to do (expecially during the summer). Please let me know, even if there is a mom/child group. Interested in it all. Thanks

Can anyone suggest something? Thanks, Rudy