At age 41, Spanx inventor Sara Blakely has become the youngest woman ever to become a billionaire. Congratulations, Ms. Blakely!  But consider this: according to Forbes.com, only 2% of self-made billionaires are women. Let's get those numbers up, girls. Oprah is getting a little lonely on top. In celebration of the success of Sara Blakely, Spanx, and women everywhere, here's a list of billionaire sisters who are doin' it for themselves.

[Sara Blakely, Oprah, via]