You can be a full-time employee whose only job is doing chores, but that's not what's described here, it's just doing (some of ) the household chores for a single house/family which you're living with
There is even a term for it, though the practice has been falling out of fashion
https://en.m.wikipedia.org/wiki/Au_pair
To be clear, I'm not arguing that this practice is in line with the tourist visa. I'm saying that calling that work is not what most people would understand under that term. And she most likely wasn't even aware that this (probably) wasn't permissable. My issue is your miss characterization of her doing this knowing that it's not allowed. Young people usually aren't very informed, and you're pushing a narrative of her going there for gainful employment, when she's likely just doing this to experience life in another culture for a few months.