jenni,
i've ridden with the bike gallery women on occasion (not as often as i'd like!) and it's a great group. if you're riding that much during the week and averaging 18 mph, i assure you that you will NOT get dropped. not to mention, it's a "no rider left behind" ride, they always stop and regroup or have set meeting times/places to regroup. don't worry a bit! i'm planning on going this weekend (couldn't make it last week due a soccer game scheduling conflict) - will you be there?
jj