It is at least positive enough that she's taking advantage of it. Even back when slavery was legal and considered socially accepted there were *still* abolitionists who refused to use slave labor. The fact that she *might* be uncomfortable with it does NOT change the fact that she's benefiting from it.
She takes interest in people who may be useful to her. it doesn't matter to her if that person is a girl lost in the street, a burglar, a man with no manners, an old geezer who lost his job, a sick girl, a slave or even a former enemy.
She takes interest in Luins' business for that reason, since his way of doing business is not far from what we see in our own world with the unemployement system (that could be a step in that direction btw, since it's noticed to be innovative... why slaves would be the only person who would benefit from a system like that and not people who lost their work ?).

I just love when stories are like: ‘slavery is fine, because these slaves are happy!’ It’s a lazy story telling trope to dance around creating real relationships between characters. And bolster the main character as a ‘good person’ because they treat their slaves well. This person follows you because you own them. And the fact you showed them basic human kindness is not a reason for loyalty. I can see it now, the slaves she buys will eventually pay off their debts and then choose to stay with her on their own accord!