From Riches to Rags — Mairsile Leabhair

A bad-girl billionaire, accepts the ultimate challenge from a waitress, and gives up all her money, expensive toys, liquor, and women, to live in a run-down building, working at a barbeque restaurant. She only has to last thirty days, and suppress her growing feelings for the waitress. Just thirty days, but to a billionaire, that's a lifetime. This is a multi-first-person point of view novel.