"I saw myself in her," Winfrey told PEOPLE at the Governors Ball after Sunday's Academy Awards. "This whole roller coaster that happens to you when you're passionate about something – she wasn't even thinking of being an actress; she just auditioned. And now here she is, being nominated alongside Meryl Streep, who is the greatest actress in the world, with Sean Penn reading her name. Only in America."
Sidibe, 26, who was nominated for Best Actress for her first film, Precious, told PEOPLE she had no idea Winfrey would be introducing her. What did it mean to her? "It means that I just might be a movie star," Sidibe said.
In her tribute, Winfrey compared the actress to "a true American Cinderella on the threshold of a brilliant new career." She continued: "And 'precious' is but the first of many adjectives coming your way – and they are all great."
Sidibe was accompanied to the Oscars by her mother, Alice Tan Ridley, who beamed at her daughter's accomplishments. "I'm so proud of her," she told PEOPLE. "This will be a lifetime memory for her. Oprah brought me to tears talking about my daughter tonight."