Mary Kate Olsen or MK (nickname) is 4’11 inches in height and was born on June 13, 1986. She has a twin sister named Ashley who is 2 minutes older than her, and is an inch shorter than Ashley. They started their acting career in 1987 to play the character of Michelle Tanner in Full House, a tv series. MK and her twin Ashley at age 6 became the youngest producers in history. Before they reached the age of 10, they became the youngest self-made millionaires in the whole American history. On June 13, 2003, their 17th birthday, CNN declared not only their birthday but also stated their total financial worth which is $150,000,000 for each of them. CNN also concluded that at the age of 21, the twins may be billionaires already. Her total wealth is approximately $137 million in 2004.