She is broken yet she keeps going doesn't give up that's the main reason i see determination. Shes also selfless for this reason cause if she gave up and just stopped broke completely then her captivators would go after her family for that and probably get them sent to jail and then she would more than likely be gotten rid of for being useless.
But shes broken from fear complete exhaustion. This leads to a dull empty kinda personality mostly from a lack of communication.
This is a common event
several people are put in slavery by people they trusted and while in slaver go through some of the hardest and most difficult challenges of their life breaking them down with each day that passes and yet they keep going and make it they have a motive just like Shyima Hall. Some motives are to help or protect others some are motivated by survival hope and or anger. But they all survived some how and none of them wanted to be this "property" as many people saw them as. Hema was a 12 old child only a few years older than Shyima when she was put into slavery Hema was the oldest child of five children and didn't go to to school cause she had to do chores and take care of her younger siblings as her parents were unable to do so them self's so she did just as Shyima and Hema's family didn't have enough money so one day a man came and offered the children work they excepted with out resist not knowing what would actually come from this. they were taken and not payed. they had to work for a wealth family and work to exhaustion and even after that just as shyima did.