From the Amazon listing:
Mestra, daughter of the King of Thessaly, is granted a unique gift by Poseidon: the ability to transform into any being she can imagine.Her father, on the other hand, is cursed: As punishment for disrespecting the goddess Demeter, he is in possession of an unnatural, insatiable hunger.Devoted Mestra suggests using her new gift to help her father. But if his hunger is bottomless, how much will he take from her? Soon she must decide: Will she keep helping her father survive, or finally break free?
Speaking of Miller, I recently listened to the audiobooks of Song of Achilles (performed by Frazer Douglas) and Galatea (performed by Ruth Wilson). Both readings are great, and I found them in the Libby app.