When Gloria Richards isn't acting on off-Broadway stages, she travels with billionaires' kids, often whom she's never met, across the world.

Richards spends half of each year nannying for the ultra-wealthy to supplement her income between off-Broadway and one-woman shows in New York City and Virginia. The gig pays her up to $167 per hour, plus covered flights and accommodations, she says — meaning that caring for billionaire's children makes up 80% to 90% of her annual income.