Ever heard of Storybird?
It’s an online tool that lets anyone create a visual story. Storybird curates artwork from illustrators and animators from around the world and makes it accessible for writers of any age to turn these images into new stories. Storybird strives to be family-friendly and they even have many children-authors who participate!
To find out more about this tool, check them out on their website here! Signing up is free!