Is it possible to write a book without feedback from people?

My cousin offered to edit my writing cause she runs a tutoring business with over 150 employees but I don’t want to take up her time when she is busy. She will probably edit it herself to prevent people from stealing my idea. Another cousin is jobless but has millions from his dad and runs family investments but he doesn’t have a background in my topic of interest. My friend is willing to help but not too intelligent.

Is it possible to write a book without feedback from people?
Post Opinion