Our parish has a Mother’s Group which is pretty similiar. We meet once a week at the church hall. The school sends the 7th and 8th graders to help out with babysitting so that the kids CAN go into another room and play. Some (mine inlcuded) chose to stay with us. It is more for us (moms) than the kids in the sense that we do not do child projects and crafts like I think some of the MOPS groups do. Each of us take turns leading a week - by chosing a topic to discuss and bringing a snack. Several of us also meet outside of the regular group and so activities on our own (play dates, walking, etc). If your parish does not have something like this, it would not be hard to set up and I bet you would find a lot of interest.
Good luck!
J