The singer is already mother to three-year-old Wyatt, who she adopted in 2007. She has now announced she has given another child a home, adding she is thrilled to be a mother again.
"I have some exciting news to share with you guys - Wyatt has a new little brother! Levi James was born April 30th," she wrote on her website. "Just wanted you all to be the first to hear the good news!"
No further details about the adoption have been released.
In 2008, Sheryl discussed her decision to become a single mother. The 48-year-old explained it took her a long time to realise there is more than one way to have a family.
"A family doesn`t always look like girl meets boy, they fall in love, they get married, they have a kid," she explained. "I said, `OK, I`m going to let go of what I think things are supposed to look like, because I can`t control anything. When I try to control things, that`s when I keep things from happening.-"