Stephens, the American football player John Stephens 's daughter, began at the age of nine with the sport of tennis. She was first trained by former professional tennis player Nick Saviano and Roger Smith, and later by former world class player Paul Annacone.
In 2007, she played her first tournament in Brazil on the ITF Women's Circuit. In 2008 she won the ITF doubles tournament in Wichita (USA ) on the side of Christina McHale. 2011, she then won her first ITF singles title in the Italian Reggio Emilia.
At the U.S. Open she reached in 2011 in the women's singles with a Wildcard the third round, where she lost to Ana Ivanović in straight sets. In doubles, she failed at the side of her compatriot Alison Riske in the opening round to Flavia Pennetta of mating / Gisela Dulko.
At the French Open, she moved in 2012 for the first time in the second round of a Grand Slam tournament, one in which they defeated the former finalist Samantha Stosur 5:7, 4:6. At Wimbledon, she was disqualified in round three against Sabine Lisicki ( 6:7, 6:1, 2:6 ). At the U.S. Open 2012, she reached with victories over Francesca Schiavone and Tatjana Malek the third round, before he lost again Ivanović 7:6, 4:6 and 2:6. Your good performance brought her in early October with a new best quotation number 36 in the WTA world rankings.
With a three-set victory at the Australian Open over her idol Serena Williams Stephens reached in January 2013 for the first time the semi-finals of a Grand Slam tournament ( three weeks before that she was inferior to her at the WTA tournament in Brisbane still with 4:6 and 3:6 ). Counter Asarenka but she was then a chance ( 1:6, 4:6 ). At the French Open she retired after victories over Karin Knapp, Vania King and Marina Erakovic in the second round against Maria Sharapova in two straight sets from. At Wimbledon, she came to the quarterfinals, where they had to bend in a competitive two- set match of the eventual tournament champion Marion Bartoli.