It takes a long time to write a good book. Rita's first novel took 8-years to finish and get published!
Revision means redoing, not just giving a new word or new phrase
Children have a wider perspective than we give them credit and their literature must allow for them to grow and evolve. with he character or even see things before the character does.
Read children's literature so you, as a writer, have a better concept of how a good children's book is written.
Look at the habits that distract a reader from following the writing.
1: Spend a couple of months just imagining the tory and researching it. Create a pool of information you can pull from while writing.
2: Write sciences and dialog
3: Write MULTIPLE drafts. Rita write 5-7 drafts and each one she is clarify or fixing an aspect of the story. "I am dealing with a very big issue or what is going to be in the story and what is going to be thrown out" (Rita Williams-Garcia, Reading Rockets. 2017).
4.Language and references
5. Send off to editors and copyright editors for final drafting and revisions.