Thanks for the question. I went through the stories on my page that I personally wrote and 6 of them involved girls under the age of 18. 8 of the stories involved girls 18 or older. I didn’t count the stories people submitted to me because I can’t speak for them.
I can understand why you are concerned about the ages of the characters. When I come up with an idea for a story, I determine how best to tell it. I like there to be an authority figure in the stories because it makes the action of wetting/pooping seem more naughty/forbidden. Writing about a girl who has an accident or intentionally wets isn’t enjoyable for me if there isn’t a chance for her to get into trouble. I don’t much like writing about guys in my stories, so husbands/boyfriends/fathers are usually ignored. That leaves me with older/younger sisters and mothers - which you see a lot in my stories.
So I often write about girls either in college - still having to worry about mom - or girls who are younger. I would like to make it clear that I don’t have any attraction to young girls. If you read my stories, I often describe the girls as looking much older than the age I gave them. Either that, or I don’t describe the physical appearance of the girl at all. I am only interested in the act of peeing/pooping. The age is just a plot device I use to make my story work.
I think of it like this: Do you ever watch a movie with high school girls? How many of the actresses are actually 14-18 years old? Almost none of them. An example off the top of my head is Analeigh Tipton’s character, Jessica, in the movie Crazy, Stupid, Love. She was 22-23 at the time, but the character she played was 16 or 17.
Again, I can’t speak for other writers, but I imagine the girls in my stories to be of legal age - I just sometimes feel the need to use age to make a certain story work. I’m not focused on the age of the characters - I’m focused on the peeing/pooping. Maybe it would be better to not mention age at all since that isn’t the point of my stories.
If I am unclear on anything I said - or if you disagree with me on anything - feel free to send me another message. I hope I helped.