I stood in line with the rest of the children from my village and waited for my turn to climb into my coffin. I tilted my head up to the sky to take in these precious moments of early summer: the sun on my face, the wind pulling tendrils of hair from underneath my scarf, a hawk circling high above.
Not far to my right, I could hear sobbing. Father Davis hovered over little Jaimie while the boy's mother tried to soothe his tears. I wondered what lies she told him. Likely she was saying that he would wake up for certain, that his time in his so-called box bed was only until summer and plague season were over. I was far too old to be comforted by such platitudes. I had a younger brother, once, until they gave him too strong a dose of the medicine that puts us to sleep for three months.
 

A place were the children are forced into coma's to avoid plagues? Nice idea and this hooks really well.

I can see parents refusing to allow there children to go through with it despite it being necessary, much like how parents refuse to give there kids immunizations.
Original and if the entire 6000 words matches the quality you have here you should do well.
 

I stood in line with the rest of the children from my village and waited for my turn to climb into my coffin. That is a wonderful hook at the end of that sentence, but I think the sentence itself is a little too long which lessens some of the impact. Just cutting "from my village" makes it a lot stronger, I think.

I tilted my head up to the sky to take in these precious moments of early summer: the sun on my face, the wind pulling tendrils of hair from underneath my scarf, a hawk circling high above. Quite nice, but a bit long again and it also lessens the tension you create in that opening sentence. I see what you're doing here, but I'd prefer it if you give brief details of where these people are at the moment. You could contrast the nice sun, the freedom of the hawk with giving us a glimpse of these children queuing for their coffins--are they in a street in a field, or whatever.

Not far to my right, I could hear sobbing. Is it important that it is "not far to the right"? Maybe cut that and just have it as a short, punchy sentence?

Likely she was saying that he would wake up for certain, Not sure why, but I wasn't too keen on this. Maybe because "wake up for certain" sounds too emotionless, too coldly clinical. I'd prefer something more like "tell him that he was only going to sleep for a little while..." It might just be me, but that sounds more like something a mother would tell her child.

gave him too strong a dose of the medicine that puts us to sleep for three months. This seemed a little forced. I'd prefer the sentence to end at "...dose of the medicine." And then fill the rest in more naturally as the story develops.

And that's all I had! Great hook, you left me feeling disappointed that the story wasn't finished yet. Good luck with WOTF

"children from my village" as a phrase is a bit forced, as is "medicine that puts us to sleep for three months."

The later could be fixed with something like this:

until they gave him too strong a dose. The medicine was supposed to make him sleep for three months. He never woke up.

But these are pretty nit-picky.
 

Hmm... I'll have to think about how to change that second line.