Tides Wait For No Witch by Natalie Summers

Synopsis: A magical island. A mysterious relative. A family she didn't know existed. Inheriting a house from a dead great-aunt she’s never met should've been Sara Rivers' first clue that things were about to get weird. The talking sea otter? That was clue number two. Sara's plan was simple: stay the six months to get her inheritance, sell the house, and figure out what comes next. What she didn't…