HEART OF GEARS is a science fiction, dystopian novel with a bit of steampunk thrown in. It is targeted towards young adults who enjoy stories like the Hunger Games. [This sentence is a bit workmanlike. Where's the hook? I'd leave this para until after the story description.]
Sophie Lane made a promise to herself; [this should be a colon - yes, I'm a pedant] she will protect her sister no matter what. Level Four of the great spherical city, known as the Hive, may not be the ideal place for a widowed mother and a unregistered clockmaker to raise a little girl, but together Sophie and her mother manage to shape Ruthie into something of a model citizen, and, more importantly, keep her safe.
When an old friend re-enters Sophie’s life in need of her help, she realizes that her sister isn’t the only person she loves who needs protecting.
And when it comes to people she loves, Sophie will stop at nothing to keep them safe. [run on this sentence to previous para]
However, up until now she has never participated in a coup to help her friends and families, but she’s done crazier things for the people she loves. Unfortunately for her, her latest attempt to save her loved ones has won her a stay in the Hall of Time, the maximum-security prison that has a most effective torture tactic; [colon alert] time in the Hall is suspended. [You've lost me here - my attention is wandering]
Now a prisoner of time [and now I'm back - perhaps find a way to condense the previous para and get us to the point where she's a prisoner of time, because that's interesting!], Sophie will do anything in her power to continue to protect the people she loves, but will it be enough? Her will will be tested, her love will be tested, and if she fails, she seals the fate of the people she loves the most.
I am in my third year at Phillips (Andover) Academy and my plan, which is subject to change at any point, is to major in Creative Writing. I am also interested in languages, archaeology, fashion, and sports. [I don't need to know this - I'd rather know why you're writing dystopian fiction with steampunk thrown in i.e. what have you been reading in the genre?]
HEART OF GEARS is incomplete at 25k [if you must query before it's finished, don't mention that it's unfinished - you're going to be told to go away and come back when it's done. No one ever wants to see a first draft, especially an unfinished one]. There is a sequel in its future. [How do you know if the first one's not finished?]
Thank you for taking the time to read my query,
Overall: interesting story premise but there was a lack of oomph. I got no sense of you as a writer - or reader. Genre fiction like this needs that bona fides because, like children's books, you're entering into an arena with passionate and knowledgeable readers. If it sounds even a teensy bit like you're writing spec fic for cynical reasons, it won't work.
What you haven't mentioned: the word count, because you can't. And, again, your 'credentials' in spec fic - I don't mean previously published work, just your background in the genre as a reader.