She was nervous. She wanted to see whether they would support her going back to Indian Wells, California, to play in a tournament she had skipped 13 times since winning in 2001.
The last time she was there, she had been booed loudly and lustfully. The fans were upset and sensed some sort of conspiracy that she didn't have to face her talented older sister in the semifinals.
Venus Williams had withdrawn 10 minutes before their match with a knee injury. Many fans didn't buy it and thought it was orchestrated to give the younger Williams a chance for extra rest.
Two days later, during the championship match, Serena Williams, 19 at the time, was jeered when she did well and cheered when she fared poorly.
Then days after the tournament, which she won, her father, Richard, told USA Today that as he and Venus walked down the stairs to their seats, people kept calling him the N-word and one man said: "I wish it was '75; we'd skin you alive."
Neither Serena nor Venus has played in the tennis tournament since.
That will end Friday when Serena Williams, the world No. 1, faces Monica Niculescu, the 68th-ranked player in a second-round match.
The end of the boycott took a lot of conversations with a lot of people, Williams told reporters Thursday.
Two of the most important were with her parents.
"It was a really emotional time for me," she said, saying the prospect of the talks made her a little nervous. She told them she wouldn't go back if they didn't want her to go.
But they both said to play.
Her dad said it would be a big mistake not to come back, she said. Williams said her mother said, "I will be there for you."
Venus Williams, the No. 11 singles player, isn't playing in the tournament, but Serena Williams said her older sister was 100% behind her.
She is "very happy that I am here. And even encouraged me to come," Serena Williams said.
Serena Williams announced her return to the event in a TIME magazine first-person piece
in February, writing she would ended her boycott in the spirit of forgiveness.
She said Thursday that she didn't just have to forgive the fans at Indian Wells.
"In order to forgive, you have to be able to really let go of everything. I kind of let go a long time ago, and I kind of forgave, but I wasn't at point where I was ready to come back," she said. The timing seemed right this year, she said.
She added that she will be a little nervous in her first match at the BNP Paribas Open.
Still she was "looking forward actually to kind of stepping out on center court and letting the whole world know that it doesn't matter what you face -- whether it's something that wasn't right, something that hurt you, hurt your family. You can just come out and be strong."