Dear Specific Agent,Twelve
-year-old Annette has serious parent problems. Her mermaid mother went off to be King of the Sea after Annette
was born [if you leave 'she' it sounds like the mother went off after SHE was born]
, and her wizard dad ditched her so he’d have more time to brood about the whole thing. [can you show us here who took care of her since being abandoned?]
Then there’s the mythical sea monster – the Leviathan – trapped under dad’s kitchen. (am confused about it being mythical yet being under her dad's kitchen) Because he's a wizard - he's got it under a spell, threatening to unleash it on the mother?]
Both parents are determined to use it to destroy each other. Annette has to find the Leviathan’s song-spell and return the monster to its own world without becoming mermaid-girl soup. If she doesn’t, mum or dad might just get mad enough to set the Leviathan loose to kill. [you already said they're determined to use it to destroy each other]
MERCHILD is a middle grade fantasy complete at 37,000 words, and, while a stand-alone, it has series potential.
(personalization). Thank you for your consideration.
This is only 119 words - leaving you plenty of wiggle room to show us more of Annette's personality and explain a few things. Good luck.