She said she doesn't believe Sterling is racist, but has urged him to apologize for his incendiary comments.
An audio recording captured Sterling telling Stiviano not to bring black people to Clippers games or post photos of herself with black friends on Instagram.
The NBA subsequently banned Sterling for life from the game. NBA Commissioner Adam Silver said he would try to force a sale of the team.
"Part of the audio the world heard was only 15 minutes," Stiviano told Walters. She added that Sterling was from a different generation.
Sterling graduated from Roosevelt High School in Los Angeles in 1952. He was known as Don Tokowitz, but changed his name to help with business.
His class prided itself on its racial diversity. In the yearbook, the creed said, "Here at Roosevelt is a melting pot of many racial and cultural backgrounds... With us it's the individual that counts."
When Walters asked Stiviano about their personal relationship, Stiviano said she began as an employee, but was later paid "off the books." Sterling has reportedly bought Stiviano several cars and a $1.8 million home.
Sterling's wife is suing Stiviano in an attempt to take those gifts back, raising questions about Stiviano's real role in Sterling's life.
She described herself as Sterling's personal assistant, "right-hand man," and "silly rabbit."
"I love him like a father figure," she said.
Walters also asked if Sterling was going to apologize.
"Only God knows," she responded.
