Hi Katie! The more the merrier! The nice thing about OC Mommies, is that it is open and free, and everyone is welcome, feel free to post up events as well! What you will actually notice is that a lot of moms form little mini groups. It is just sort of natural based on their location and the ages of their babies and kiddos and then they will have regular meet ups. I joined when my son was 3 months old, and 2 years later I have the same playdate with the same 8 ladies every other week! But we are all still really active here as well! See you thursday!