LOS ANGELES - If only every daytime talk show host had a long-lost half sister.

Oprah Winfrey scored her best ratings in nearly six years with Monday's show during which Winfrey revealed that she had a half-sister she never knew.

The installment of Winfrey's daytime talker averaged a 9.6 household rating (according to metered market weighted averages). That's the highest episode since Winfrey's post-Oscar party installment on February 28, 2005.

Winfrey teased the big reveal on her show last Friday promising a "shocking family secret" that she said "literally shook me to the core."

Winfrey's younger half-sister Patricia was given up for adoption by Winfrey's mother in 1963. At the time, Winfrey was living with her father and did not know her mother was pregnant. Of course, this is not the first personal detail that Winfrey has unveiled on her daytime show. She has also revealed that she was molested as a child and lost a baby at 14.