Not really. Hard work doesn't directly equal more money and laziness doesn't make you poor. I'm sure if people were paid based on how hard they worked, her miners would be richer than she is. I'm sure she's good at what she does, but not all of us are lucky enough to be born to a father who owned the world's largest iron ore deposits, then be personally mentored and groomed by said father to run the company after it's given to us. Nepotism trumps hard work every time.
Also, a relaxed and happy employee is a more productive employee. At a certain point there are diminishing returns on working harder. Drinking, socializing and generally enjoying life and not working yourself to the bone will yield better returns. So her advice sorta fails on all fronts.