On Nathan Bransford site:
If you tell a close friend or family member that you’re writing a book, it’s highly possible they will ask to read it.
Maybe they feel obligated to ask. Or maybe they genuinely want to support you. But whatever the reason, showing your work-in-progress to close friends or family can introduce some non-trivial complications, both for your book and for your relationships.
In this post, I’ll talk about how to decide whether or not to share your work, and if you do decide to share it, how to set boundaries for the review process.