Serena Williams has a sibling.
Serena Williams . She is also the most recent player , together with her sister Venus Williams , to have held all four Grand Slam women 's doubles titles simultaneously ( 2009 -- 10 ) . The arrival of the Williams sisters has been credited with ushering in a new era of power and athleticism on the women 's professional tennis tour . The Williams sisters are two professional American tennis players : Venus Williams ( b. 1980 ) , a seven-time Grand Slam title winner ( singles ) , and Serena Williams ( b. 1981 ) , twenty-three-time Grand Slam title winner ( singles ) , both of whom were coached from an early age by their parents Richard Williams and Oracene Price .