Hi A.,
You can try Baby Hui, which sets up local groups of Mom's with kids of similar age groups (babyhui.org) or Windward Families for REAL: ###-###-####, which runs a free weekly parenting class that has daycare/crafts etc available. There is also something called MOMS Club, which I have no experience with but might be worth trying, their web address is home.oceanic.com/mclub.
I get the impression that you might be a military family, from a previous response. If you are, then I am assuming you would be nearest to MCBH K BAY. You should check out the Armed Services YMCA over by the hourly CDC. They sponsor play mornings and some other activities. Also the Base library has a Thursday story hour, but I think that during the summer it is a more general summer reading program. I also seem to remember that both the Kailua and Kaneohe public libraries have story hours too, but I have never tried them. Also the Dance,Movement Academy has Mom & Me tumbling classes that you could probably do while carrying the 2 month old.
I also have a two year old, who I stay at home with. But she is in daycare M,W,F....so I don't do a lot of these activiites. Recently I decided that I needed to try and find something besides gymnastics, since my little one hasn't taken such a liking to it. I am also on MCBH, so please feel free to contact me if you like. I'd definitely be up for a play date or two!