Is anybody out there? Sequels: I need your feedback

When I originally thought about my second novel I considered writing a sequel to Under the Family Tree, in which I would follow the same protagonist (Dakota Lodi) three years later. She would be 19 if that were the case and so technically it would be a new adult as opposed to a young adult novel. Instead, I went in a different direction. The story begins three years later, in the same location, and with some of the first novels minor secondary characters playing more major roles. Except it is told in first-person through the eyes of a new protagonist, 17 year old, Elijah Parker. The story is completely different but there are instances where it intersects with Under the Family Tree. I've also added Dakota to some of the scenes as well, and she plays a critical role in solving the mystery portion of the book.

Anyway, I've seen writers do this before but I'm curious as to what people think about it.