It's a sister and sister thing

Serena Williams won the Billie Jean King Cup one-day tennis event after defeating her defeating her elder sister. Well even though she wins, the sister would definitely seems not mind. It seems nice to have a sibling to play together and helps each other improve. Both of them have the talent in this game and both should be happy for one another whoever wins. After all, all the players participated get a good amount rewarded for playing.