Meet my Hatchet of Death (or, some other colorful description RC Lewis and I come up with at any given moment). This is how I edit myself, it is how I edit others. If you think you want to play with me and my hatchet, shoot us an email.
We all know the first line of a query is your "hook." I call the last line the "sinker." You want it to punch them in the face, in a nice, friendly kind of way that makes them unable to forget you after having read the 300 other queries in their inbox.
If you're looking for query advice, but are slightly intimidated by my claws, blade, or just my rolling googly-eyes, check out the query critique boards over at AgentQueryConnect. This is where I got my start, with advice from people smarter than me. Don't be afraid to ask for help with the most critical first step of your writing journey - the query. My comments appear in green.
One taunt from school bully Sammy, and Daniel Hoover, age twelve, says nothing. He’s not the type to retaliate. I like it. This is a good hook on a timely subject. Kind of a quiet hook, but it gives promise of more to come.
One punch during lunchtime and Daniel walks away. He’s not going to risk getting into trouble when he’s up for an athletic scholarship to a prep school.
A second punch during wresting practice, and Daniel staggers.
A third punch, and Daniel’s nose starts to bleed. I think we need more of a feeling of a timeline here - is this all in the same day?
Three is too much.
Do it again. Do what again? Who is doing it?
One punch, and Sammy stumbles.
A second punch, and Sammy falls and hits his head on a step.
By the end of the day, Sammy is dead.
This is the story of Daniel Hoover, a latch key kid wrestling champ who struggles to raise his mentally-challenged younger brother and keep the household running. As he fights his family’s staggering poverty and the weight of his single mother’s expectations, he longs to secure a future altogether different from the one he knows until one fateful day where he reaches his breaking point. This is a great paragraph here, with a nice summation of the concept. What you need to do is bring together the elements before this into a more cohesive linear progression, making it less abstract. I don't dislike what you're doing here - it's definitely something different - but you don't want an agent to be turned off by your first sporadic sentences and not get to the meat here.
THINK OF THE CHILDREN is a 97,000 word coming-of-age adult debut. Your genre is off. With a 12 y/o protagonist this is upper MG, possibly YA depending on content and language. Your word count is also very high for a contemporary in this age range of readers. Definitely look and see what you can pare down out of the ms before querying.