Truthfully I am kind of torn on Charlotte and people like her...she is a private citizen. She is not being supported by the taxpayer. She has no obligations to anyone but herself.
Yes. This is one area where the Monaco royals differ from other royals. They don't take tax money. They live off the investment their ancestor made setting up the casinos in the late 19th C. Though they have an 800 year pedigree, in the last century and half they've behaved as business people.
Monaco is similar to those Native American casino states, and run on similar lines. The cost of policing, street lighting etc in their tiny piece of territory comes out of the princely family's casino profits and the natives do not pay any taxes at all.
Given that, it's fine for them to enjoy the surplus left over. It's not as though they force all those millionaires to lose money in the casinos. They freely hand it over. LOL. They've not taken any money from the poor, the way our royals do.
Edit: Actually they do pay some tax in Monaco - they pay VAT of 19.6% (same as France and presumably set so the French wouldn't get cross about people crossing the border to buy stuff) and they charge corporations 33% tax on profits, unless they can demonstrate that three-quarters of company turnover is generated within the confines of the principality. In other words, small bakers and what not are tax free, but the big corps are charged tax on money earned elsewhere. Not a bad system, but one only workable in a place as small as that.