Schoolgirl Rowan Hansen wrote to DC Comics: "I love your comics, but I would love them a lot more if there were more girls.
"There are Superman and Batman movies but not a Wonder Woman one.
"You have a Flash TV show but not a Wonder Woman one. Marvel Comics made a movie about a talking tree and raccoon awesome, but you haven't made a movie with Wonder Woman.
"Please do something about this. Girls read comics, too, and they care."
Rowan's dad, Jim, posted a photo of his daughter's letter on social media – and it quickly went viral.
- David M. Perry (@Lollardfish) January 28, 2015
And DC Comics was quick to respond, first by agreeing wholeheartedly with the schoolgirl – then by creating a sketch of Rowan as a superhero.
- TODAY (@TODAYshow) February 20, 2015
Rowan, from Champaign, Illinois, told the Today Show: "I have never really understood why they've had more male superheroes.
"It's not like the male superheroes are better than the female superheroes. But there are just more of them."
Her parents Jim Hansen and Renée Trilling, English professors at the University of Illinois, said Rowan has questioned gender inequality for years.
For example, she was once annoyed that a birthday gift of 12 Justice League figures only included two female characters.
Renée told Today: "You go to the store and they don't have a Hawk Girl T-shirt, [but] they have Superman everywhere and Batman everywhere.
"I don't think it diminished her enjoyment of the stories or the characters at all. But it made her feel like she couldn't quite participate in the way that she wanted to."
Jim added: "[She'd ask], 'Why does Wonder Woman always have to be caught by Superman? Why doesn't Wonder Woman ever catch Superman?'
"I was like: 'These are good questions.'"
DC Comics responded to the viral letter, writing on Twitter: "Thanks Rowan. We agree, we're working hard to create more superhero fun for girls!"
They added: "Yes Rowan, girls read comics too! Wonder Woman movie & Supergirl TV both in the works, with more exciting girl power announcements soon!"
A couple of weeks later, DC created the sketch of Rowan flying through the air in a superhero costume."
Rowan said: "I was just, like, 'Oh, my God, I can't believe this. It was really, really cool, because they're so big and important people."I want people to keep trying to make this happen, because it's really important to me."
Jim suggested the cartoon sketch should be placed above a mantelpiece - and his daughter was in agreement.
Rowan said: "It needs to have, like, a place of honour."
When DC asked her if she'd like to pen the script for a Wonder Woman movie, she accepted - but only after she's finished fifth grade.
More on Parentdish: