Couple years ago I was No. 7 and I ended up top. So I kind of like the position that I'm at right now. It's hot.

I don't have anything to prove ever, ever in my life. If I have something to prove, what does that mean for everyone else? And I think everyone should have that attitude. You just have to prove to yourself that you can go out there and be the best that you can be and not prove anything to anyone.

For the younger sisters, we always look up to the older sisters because they're always ahead of us and they always win.

Will I have to explain to my daughter that her brother is gonna make more money doing the exact same job because he's a man? If they both played sports since they were three years old, they both worked just as hard, but because he's a boy, they're gonna give him more money? Like, how am I gonna explain that to her? In tennis we've had great pioneers that paved the way - including Venus [Williams], who fought so hard for Wimbledon to pay women the same prize money they pay men, and Billie Jean King, who is one of the main reasons Title IX exists.

I am not a robot. I have a heart and I bleed.

I've never felt invincible. I've never used that word to describe me ever.

The red kind of symbolizes a lot of things I do in Africa, along with a lot of the work, like the red laces. Everybody that buys a pair can pretty much save a life in Africa.