Flora in Love — Natasha Farrant

Just when Bluebell thought her crazy family were behaving normally, her parents make an announcement that could turn everything upside down. If only Zoran, their au pair, would come back to live with them. Unfortunately he's too busy teaching guitar to his new protégé, Zachary Smith. Blue is jealous at first, until Zach starts helping her little sister with a secret project and becomes a regular visitor at the Gadsby house. Then Zach goes missing. Blue needs her family to pull together if they're going to find him...