Hi Jane, yes facebook is good fun and also a helpful marketing tool. There are all sorts of good and wonderful networking groups on the place, even got a UKBF group on there.
I just tried searching for you on the place but search facility aint working at the moment, so I can't go ask you to become a friend.
Have you posted up your group on your local marketplace, as its a local thing? Also join other groups related to it and post on their boards etc, much as you would do on here. Also send out messages to all the friends you have on the place, go search the groups and get people to become friends with you etc. Its all about spreading your network across what you feel is relevant groups.