Oprah Winfrey has had a reunion with a half-sister she didn't know she had.

Speaking on The Oprah Winfrey Show Monday, the chat show host announced she had discovered that a Milwaukee woman named Patricia was her half-sister.

"This, my friends, is the miracle of all miracles," Winfrey said before bringing out the 48-year-old woman, whose full name was not given.

Winfrey said her mother had a daughter and gave her up for adoption in 1963, when Winfrey herself was living with her father.

Winfrey was born to unmarried teenage parents and raised by both her maternal grandmother in Mississippi and her mother, who moved to Milwaukee. She spent part of her youth with the man she considered her father, Vernon, in Nashville. 

Her mother never spoke to her of the half-sister. Winfrey is nine years older.

Winfrey's mother Vernita Lee said she never admitted she had another daughter "because I thought it was a terrible thing for me to do, that I had done — gave up my daughter when she was born."

"I made the decision to give her up because I wasn't able to take care of her," Lee said during a recorded interview that aired Monday.

Met on Thanksgiving Day

Winfrey said she learned about the half-sister last November and met her on Thanksgiving Day.

Winfrey said the woman searched for years to discover the identity of her birth mother.

Patricia had been bounced from one foster home to another until she was adopted at age seven. She said a Wisconsin adoption agency told her her birthmother had refused to meet with her.

But in 2007, she heard an interview with Lee, who talked about two of her children who had died.

Patricia compared her date of birth with the story of Lee's missing children. She quietly got a DNA test, comparing herself with the daughter of Winfrey's dead sister in Milwaukee.

Winfrey said Patricia had known since 2007 that the two were related and had tried unsuccessfully to contact Winfrey, her mother or others in Winfrey's family.

"She never once thought to sell the story," Winfrey said, congratulating her half-sister for not trying to profit from the relationship.

"Family business should be handled by family," Patricia said. "It couldn't be handled by anyone else. That's not fair. It wouldn't be fair to you."

With files from The Associated Press