#Alice#Walton # Other notable self-made women include Rihanna ($1 billion), Spanx founder Sara Blakely ($1.4 billion), and Taylor Swift ($2 billion). Another newcomer is Luana Lopes Lara, a former ballerina from Brazil who co-founded the prediction market firm Kalshi. At 29, she becomes the world’s youngest self-made female billionaire, taking the title from 31-year-old Scale AI co-founder Lucy Guo ($1.4 billion).