Luzai is not aware, for the first several years of her life, that anything is wrong. 

Her mother loves her and her brother dearly; her brother is a fine playmate, and the other children respond well to Luzai's incorrigibly friendly nature. Some of them are less healthy than she and Villibor are, and that is sad, and she learns to be careful with them, but it doesn't strike her as cause for concern. The governess brings all of the children out to the channel every night, so any injuries they pick up don't stick, and someone comes in to cast Remove Disease when they get sick. 

She knows, in the abstract sense that children know things, without fully appreciating the context, that there are lots of kinds of people. That she and Villibor and the other children are dhampirs, and Mama is a human, and so are most of the other children's mothers, except for Miss Zora who is an elf, and Miss Q who is an Aasimar and Miss Eshe who is a tiefling. The governess is a ghoul, and so is the cleric who does the channeling. The servants are zombies and skeletons. 

It takes longer for her to understand that the zombies and skeletons aren't just normal people who aren't allowed to respond to questions. That Mama and the other mothers don't come out for the evening channel, not because grownups don't need channels, but because they are quick and so the kind of energy that heals little dhampirs and ghouls and skeletons hurts them. That ghouls and zombies and skeletons, and all the other kinds of dead that roam the city like devourers and mohrgs and specters, all used to be quick, and now aren't. 

That there are other ways of dividing people than by race. That the reason Mama and the other mothers can't leave the estate is because they are a kind of person called slaves. 

Luzai can't remember most of this learning, later. By the time she's twelve she can't remember a time when she didn't understand the world around her well enough to be enraged by it. 

Luzai gets away with avoiding necromancy as much as possible, and focusing on Enchantment instead, in her wizard studies, because by the time they've gotten past hanging cantrips all their tutors think of Luzai-and-Villibor as a unit, to the extent that Villibor's necromancy is seen as as good as hers, too, which is sort of accurate from a practical standpoint but usefully obscures the sheer rage and guilt she feels when tasked to call a soul back from their reward to enslave it to a suit of bones or rotting flesh. 

They're planning to leave. They were always planning to leave; Mechitar isn't the sort of place where you can live a life, in the long run. Only a death. 

When Mama dies of an injury that could have been healed, trivially, if positive energy were permitted in the country, Villibor reanimates her and the three of them run.