I should add: many adult children are happy to write at a discount or lower wage for relatives! It's just relatives expecting you to write a long biography (the standard length being a whopping 400 pages to get traditionally published) without payment is really, really rude. If I wanted my parents to write a biography for me, I would at least offer to pay them. Because it's hard work! And there's so many biographies out there, that writing one is actually competitive.