Let the story arrive out loud
A child can tell a story before they can comfortably type it.
Voice input can separate storytelling from keyboard skill. The grown-up's job is to protect the child's phrasing while making sure the captured idea still describes the page they want.
Ask for a picture-sized moment
Invite the child to describe what we should see on this page. Speaking about one visible moment is usually easier to capture than dictating an entire chapter. If the child continues into later events, save those ideas for the next pages rather than cutting them off.
Review meaning, not grammar
Transcription can mishear names or unusual words. Read the captured idea back and ask whether it means what the child intended. Correct essential names and actions, but avoid rewriting the sentence into an adult voice unless the child requests it.
Use the picture as the next speaking prompt
When the image appears, let the child react aloud. What surprised them? What should be different? What happens because of what they see? The picture turns the blank-page problem into a conversation with something concrete.