Hello!
How wonderful! Congratulations to the young author. I am a creative/academic writer focused on Ghostwriting. I have experience writing fictional novels and short stories; as well as blogs, articles, content writing, taglines etc.
I have also experience teaching; so proofreading/editing is part of my job. I am, also, a really fast reader and look forward to read the material your son wrote.
If you give me 10 days, you can be sure the book will be in perfect shape!