Oba and the Boat

Oba's a mermaid.  More importantly, though, she's a career girl; ambitious, motivated, and destined to be chief one day. Nothing can stand in her way. (Well. Float in her way.)Except that thirty minutes into her first ever job - delivering correspondence across the ocean to a neighboring tribe of merfolk - she screws up. She loses her chief's amulet, an irreplaceable treasure that marked her out as a legitimate maritime messenger.
Even worse, the amulet is found and taken away by that most terrible of things: A boat. Boats, Oba knows, are where humans live. Which means that she's just allowed proof of her people's existence to fall into the hands of their mortal enemies. Oh, she is so fired. Not content to give up her dreams nor able to endure the mockery she knows will await her back home, Oba decides to take her dilemma to the local sea witch.
And. well, when has that ever worked out for anyone, honestly?FANTASY, YOUNG ADULT, COMING-OF-AGE, F/F