Kylie Cosmetics' 20-year-old Founder Kylie Jenner, with a net worth of $900 million, is the youngest member on Forbes list of America's richest self-made women released on Wednesday. Kylie, who appeared on the list for the very first time, amassed the fortune in less than three years. Roofing supply company ABC Supply's Diane Hendricks topped the list with $4.9 billion.