I was my daughters daisy scout leader this past year. We had a hour and a half meeting, ever other Tuesday. We also tried to do one outing a month, but that didn't always happen.
Most of the petals we took care of during the meeting. Some of them, we only did discussions about. There school had a "Help beautify your school day" where we planted flowers and pulled weeds around the school, so we all went to that for one of the petals (I don't remember which one). The one that delt with taking care of yourself, we made a couple of healthy snacks. We also went and visited the local police department for the respecting authority petal.
One thing I would suggest. Have a back-up plan for any of the girls who miss a meeting where you are working on a petal. They can always just discuss it with their parents at home. Since the petals go in a little circle, it is obvious if a child doesn't have one, and that can really hurt their feelings.
Good luck. The Daisy's are a lot of fun. As long as you have a game, snack and craft, they are happy!!