Interesting. I've been working on the same problem (you need stuff at a kid's level, but not aimed at kids, if you are interested in the content then it will be easier to learn): https://tailoredreaders.com/samples

I think I like your solution better than mine, which is basically generating children's books from user prompts.

When you say you generate stories from the films, are you summarising / simplifying the narrative of scenes in the film (to down level the language), or creating something new, just with the vocabulary the film uses?