Actually, after
@Nytem4re's post, I did want to point out a detail about how Igraine runs the drug cartel (or manages a portion if you don't think she's high ranking enough to be in charge of all or most of it).
Primarily, selling drugs is a lucrative source of income, but secondarily, it's a source of blood. As addicts become increasingly addicted, they buy more and more of their preferred drug, usually racking up a massive debt. The cartel promotes this, up to a point, as long as the amount made from the victim in the past is much more than they currently owe. Eventually, said victim would run out of money and be unable to purchase more drugs, and the victim will be 'strung along' with loaned drugs until one day, as the victim comes in to borrow just a bit more, the cartel kills him, hangs him upside down, slits his throat and collects the blood. Depending on their drug of choice, their corpse will be 'marked' a certain way, giving the impression that different gangs control different drugs. Their bodies will be disposed of in various different fashions as well to give the same impression. If the victim is poor, no one would care much, but if the victim is rich, the shame of having an addict in the family is usually enough for noble houses to keep the death under wraps for the most part. The manner of death, thanks to the unique markings, would lead investigators to know immediately that the victim was an addict as all previous victims with said markings and methods of disposal were addicts upon further investigation.
Igraine did not come up with all these ideas herself; she either inherited them from someone else who used to run the cartel, or it was suggested to her by underlings. But it's been a good plan so far and she's kept it going. it keeps a steady supply of blood coming into the house, though some do worry about the effects of blood laced with narcotics.