There was one couple (out of 3) in our group that already had a child. We did hypnobirthing (totally recommend it btw!) and so they were doing the class for #2 because they'd heard about it since baby #1 and wanted to try it.
My coffee groups were formed by a couple girls who lived in my condo and then we all invited one or two more people we met through things like prenatal yoga/AN classes/colleagues who happened to be pg at the same time ... and the other one was the group of girls who came to Baby Cafe around the same time as me (BF support group).
And I feel like I have an online coffee group with the other Feb 09 Mums from here, almost as good (and sometimes better!) than my RL coffee groups