No one in Destiny’s Child was Beyoncé’s younger sister; her younger sister is Solange Knowles.
Destiny’s Child was a vocal group whose best-known lineup included Beyoncé Knowles, Kelly Rowland, and Michelle Williams. Although Beyoncé and Solange are both professional musicians, Solange was never a member of Destiny’s Child’s main lineup.
Solange Knowles was born in Houston in 1986 and later developed her own career as a singer, songwriter, producer, and visual artist. She released albums including Sol-Angel and the Hadley St. Dreams and A Seat at the Table. Her musical style and public work are distinct from Beyoncé’s, even though the sisters have occasionally collaborated.
This relationship is often confused because Kelly Rowland was raised for several years with Beyoncé’s family and is frequently described as a close sister figure. Rowland, however, is Beyoncé’s former groupmate, not her sibling. The family connection is specifically between Beyoncé and Solange.