Kids...really don't watch Sailor Moon.
As the topic creator
noted in another thread (albeit for a different reason), Sailor Moon is an old anime and there aren't that many kids who are watching Sailor Moon these days.
Even among anime fans, Sailor Moon -- while seen as a classic -- doesn't get that much traction.
I would counter that Sailor Moon is very well known and recognizable -- she is very iconic and she won't be forgotten in our lifetimes. It's not as if Sailor Moon's brand is dead and unable to be revived. Plus, given the nature of the costumes, the franchise is always going to be a staple of cosplayers. However, the actual fanbase is definitely made primarily of adults 25+.