Hi Angela,
I'm northern beaches and have gone to the SAP meet ups in the past - there hasn't been one for a while but a few of us are looking to give it a bit of a kick start in the next few weeks (probably next wednesday). If you join the SAP list you'll find the info there.
There is also a playgroup at Kinma in Terrey Hills every monday during term time. Not strictly an AP playgroup but lots of AP mums there. It is from 9.30 - 11.30am, and visits are on a casual basis $3. Everyone is welcome. Check out
http://www.kinma.nsw.edu.au for more info and location, or pm me. I'd be happy to give you more info.
Cheers, Jenny