Hi! So there are 6 levels of the Girl Scouts: Daisy, Brownie, Junior, Cadette, Senior, and Ambassador. Ambassadors, the highest level, are girls in 10-12 grade, so around 16-18 years. There is such thing as Campus Girl Scouts, for college girls. They don't count as a troop or sell cookies but it does help keep you connected around campus. That's pretty much the closest you can get to being a girl scout once you're out of high school. If you are an adult, you can volunteer to be a troop leader and you don't need a kid to be in the program to do so. Hope this helps!