Marcy's parents drill her on situational awareness and psychology. The Boston enclave tutors drill her on languages and melee combat and ranged combat. Her friends all drill each other on all of it, at lunch and on the weekends and on the outings everyone in her year goes on together so they can be a tight-knit high-trust group. They're constantly competing to see who can be first to translate a sentence or run to the end of the hallway or do fifty pushups or scale a fence or throw a pencil across a room and impale an apple. Different people win at languages on different days, but Marcy always wins at throwing things, because her affinity is projectiles and when your knife can come back to your hand it's worth getting good at throwing it.

And when Marcy's alone, she drills herself more, because if you want to survive it's not enough to be good. Plenty of dead kids were good and she has to be better than them. She conjugates verbs in the shower and stalks mals in her dreams. She speaks eight languages and knows how to make her own crossbow and bolts and she totally might die but if she does she's going to go down fighting.

When it comes time to pack they all coordinate with each other. Some things everyone needs their own of, especially with the rooms being who knows how far apart, but other things--medicine and spell supplies, mostly--can be redistributed and passed around once they're in there, if that's what will save on containers. Marcy ends up with a lot of their shared trade goods because her body weight is so low and lets herself be smug about it when nobody is looking. She knows they have to stick together and help each other but if she wants to privately attempt to be the best and most helpful one in the group then so much the better for all of them.

She loads up her bags with medicine and letters for older siblings (none of them hers, she's the oldest of six, spaced one every year like clockwork) and alchemy ingredients and dental floss and clothing (but not underwear, who needs underwear), and shaves her head and eats steak and cheese and chocolate bars and buttercream frosting out of the can and the day before they leave she eats absolutely no salt, because salt makes you retain water, and nothing for two hours before induction because she would just puke it up anyway. 

Also on the day before induction, they meet up for the last time outside, and they all put their hands on the same stack of dictionaries and pledge to each other their lives, their fortunes, and their sacred honor. It's an old tradition but they all mean it, and they each know in their bones that all the others mean it.  

She does her final weigh-in and hugs her parents goodbye and tells her oldest younger brother not to worry, she's going to clean out the mals for him. Her ten-year-old sister says "I triple dog dare you to come back alive," because Marcy always told her that if it's a triple dog dare then you have to do it. Marcy absolutely refuses to cry about this and thank goodness she only has to pull that off for five seconds because now she's gone.