The now - 35 - year - old Hingis and her doubles partner , Sania Mirza , are currently the top - ranked doubles team .
Hingis returned to professional tennis in 2013 and has since won six Grand Slam doubles titles .
The now - 35 - year - old Hingis and Hingis ' doubles partner , Sania Mirza , are currently the top - ranked doubles team .
Hingis returned to professional tennis in 2013 and has since won six Grand Slam doubles titles .