Beatrice and Eugenie, along with Pippa and Kate, are leading exactly the same lives as their peers.
West London is full of rich kids killing time one way or another before they make a good marriage and have children.
Some of these kids work in the family firm, or in the PR firms, catering companies or art galleries of their parents' friends.
The ones with a bit of brain work in financial services. As you might imagine, they're often very good at moving money about and charming important clients, as they've been doing it since they were small.
They all go on holidays together, staying at their parents' holiday houses and yachts, so their sixteen holidays don't actually cost that much. Their designer gear is bought at huge discount because another friend's parents will have a chain of boutiques, or a distribution licence (both wonderful forms of tax avoidance), or because mummy is friendly with a designer whose label is secured by daddy's private equity house.
They lead a charmed life with no concept of needing to work in order to pay bills or make the rent. They want to "do something creative" (jewellery/interior/fashion design) and the more sensible ones want to do something "fulfilling" (charity work, usually involving india or africa so fabulous holidays can be tacked onto the back).
I'm not excusing the princesses; I'm just saying that's how their world works. My work services their "needs" and their wealth trickles down to the people I employ, some of whom really need the money.
India seems to have the right idea about its royalty - you can keep your castle but now you need to turn it into a 5 star hotel and live off that.