Again, I think it's fabulous that you're putting up the flyers and forging ahead, I think you'll do really well and have a great time with cycling. The fact that women are answering your flyers for beginner rides means that there's a need for a beginners riding program, AS well as a lot of women interested in cycling, and kudos for you for going out and starting it.
WOMBATS stands for Womens Mountain Biking and Tea Society. It's a thing started by Jaquie Phelan who was the first great proffessional woman mountain bike racer, really in the early days of the sportback in the eighties? or so. It's a loose national network of women who ride dirt, you pay your dues and get your T shirt and a membership list. She teaches now, all dirt riding, but the whole BAT idea is that in a very male dominated sport women can start their own clubs and ride hard and still be women. And have a lot of fun. Jaquie is very much a free spirit, and famous for racing in frilly blouses and pearls- just to make a point. She can leave most guys in the dust.
The most important point though, is the teaching. Cycling is terrible for telling beginners anything, especially women. You may have noticed that. The lack of beginner rides? The lack of freindly coaching, teaching, advice? Mt biking requires a lot of technique, none of which is rocket science but none of the men wanted to tell the women how to do anything for years! Jaquies clinics are meant to be empowering experiences as much as teaching the technical side. Once girl can hop a log, not much else will scare her.
The membership rides, however, are pretty intense. I've never been on one 'cause there are no BATs here, but I've heard. And this is all mt biking so it does you no immediate good, but it's good to know about. Up with women on bikes!

Lizzy