After years of closely guarding her privacy, Beyonce has spoken openly about marriage, motherhood and giving birth.
In the singer's new documentary, called Life Is But A Dream, she talks about her life with rapper husband Jay-Z and their daughter Blue Ivy.
Coinciding with the documentary, which aired in the US on Saturday, Beyonce talked to Oprah Winfrey in an interview shown on Winfrey's OWN channel.
The film, which Beyonce co-directed, is part of a return to performing after a year off since Blue Ivy, her first child, was born.
She told Oprah how she had gained almost 60 pounds when pregnant and was shocked when she went to perform again for the first time.
"I did a show three months after I gave birth, which was really crazy. I had clearly never given birth, and I didn't know that I would gain 60 pounds...," she said.
Pressed further about the weight gain, she said: "Yeah, 57 pounds."
Of motherhood, she said: "My daughter introduced me to myself. Motherhood made everything make sense."
Blue Ivy was "hilarious and smart", she added, saying: "She's already reading flash cards."
Asked if she planned to have more children, she told Oprah: "I would definitely like another", telling the presenter to check in again after her new tour.
The star also spoke tenderly about her husband of almost five years, saying: "I would not be the woman that I am if I did not go home to that man.
"We were friends first for a year and half before we went on any date - on the phone for a year and a half. And that foundation is so important in a relationship.
"Just to have someone that you just like. You know? It's so important. It's someone who is honest."
Beyonce, 31, launched her comeback last month with a controversial lip-synched performance of the national anthem at President Barack Obama's inauguration in January.
It was followed by a live performance at the Super Bowl half-time show that wowed critics.
Her documentary shows the star putting herself and her team through gruelling choreography rehearsals in 2011 and planning every second of her performances at big awards shows that year.
The singer is due to release a new album this year and her 40-date Mrs Carter Show World Tour across Europe and North America will begin in April.
She told Oprah: "I feel so fortunate to do my job. I love my job. I love singing. I love the way it feels."