Post History

Setting aside your specific case, which I'm not qualified to comment on, I'll address your general question of a 13-year-old opposing family and the broader society's ethics.  I have no particular expertise in history or sociology here; this is just what I've observed.

Sure, this happens quite frequently in other ways -- consider teenage religious rebellion, which is sometimes just "rebellion" but sometimes actual disagreement with the ideas the child was indoctrinated into.  The more a set of values or ideas is presented as "just how we do things" and the less it's presented as a reasoned outcome, the more susceptible it is to challenge.

*However*, that questioning needs a *seed*, a reason for the teen to doubt.  That seed could be exposure to the negative consequences of the value -- for example, seeing the harsh effects of slavery on someone who, as it turns out, is more human than animal after all.  It can come in the form of reading or hearing new ideas from credible or loud sources -- the tutor you mention, influential friends, a prominent member of society who questions those values too, people the teen meets at summer camp (I realize your character doesn't have summer camp).  It can come from reason, if the setting is right -- parents who teach a child to be analytical, scientifically rigorous, or curious can have that come back to them in unplanned ways.  (This was my experience with religion as a pre-teen and teen.)

Without a seed of some sort, I would posit that going against one's culture as a teen would be vanishingly rare.  We in the ultra-connected 21st century are used to encountering people and ideas very unlike ours, and even *we* can be slow to adjust the assumptions we take to be universally true.  When your character's whole world is the local culture and whatever outside news filters through it, the character is going to need *some* sort of "hook" to start thinking differently.