According to Media Takeout, the 23-year-old singer has said that Rowland lived with her family when she was a child and that her mother was their family nanny.
When asked about Sandra Bullock's adoption, Knowles told MSNBC: "I think it's a phenomenal, beautiful thing. Kelly Rowland actually grew up with us. She moved in when she was 5 and so we have sort of a blended family.
"I've only ever looked at her as a sister. I think adoption is a beautiful thing."