I was in the Central Bucks group 3-ish years ago. I'm sorry but I don't recall if there were extra activities besides the meetings. The one thing I didn't like about the HMN is that you have to pay to join & I never was sure what you got for the money. They have a members only yahoo group (which is free) and they sent out an online newsletter. I imagine some groups have to pay for meeting space, but I know that groups try to find free space. My first experience w/ meetings like this was LLL mtgs., so perhaps from my experience of being able to participate for free, I'm a bit colored on the subject ;-).
If you are interested in meeting with other moms who are on the holistic side of things, maybe an LLL meeting might be a place to find someone? You don't say how old your child/ren are...there are two La Leche League groups that meeting in Montgomery County. This group has a meeting coming up on Monday night at 7pm: http://www.lllusa.org/web/MontgomeryEastPA.html There's also this one: http://www.lllusa.org/web/MontgomeryCentralPA.html Depending on where you are in Montgomery County, the Doylestown group may be close enough to you (I live in Montgomery County & starting going to the Doylestown group years ago ;-)): http://www.lllusa.org/web/DoylestownPA.html The Doylestown group used to have playgroups; maybe they could be revived?
Oh, there's also a website called northpennunderten.com. You won't find specifically holistic events on it but there is a ton of stuff listed. Do not just go to what is listed though - call first to check. When I was looking at it last weekend (really for the first time more than just glancing over stuff), I found at least one thing that was listed incorrectly.