Help specifying why a family is screwed up

In one of my stories, the main character asks her friend to kill her family (bar herself and her brother) for currently unspecified reasons.

its not a large part of the story...yet, so i can mostly just get away with implying the family did something horrible, and leave it at that.

but i dont really want to do that. while i dont intend to actually reveal what they family did in this story, i do want to at least hint as to what it is, so attentive people can pick it up themselves. but for that i need to have an idea what the family did.

At first they were going to be Blackmarket Organ harvesters, and bred children solely for the sake of harvesting their organs, and was the reason the main character was so unwell.

buuut i decided against this since it causes several problems with the plot...but thats really the only idea i can come up with that would affect the main character as a child, and make her resent her family, and remain a "business" type of thing (the villain of the story was closely associated with the family's line of work).

can anyone help?

They could be cultists who believe in prayer medicine, which means that any actual infections will pretty much kill them, and possibly already killed one of their siblings, with maybe the brother needing some basic medicine that he can't get because of the parents.

Abuse, whether sexual, physical, or "merely" verbal, could be enough. For that matter, depending on the age of the protagonist and their amount of self-centeredness, any kind of slight, real or perceived, could be enough. If the protagonist is more the Lawful Good type, then any kind of moral failings by the parents could be enough.