Beyonce is in no rush to build a family with her hip-hop mogul husband Jay-Z - insisting she's "not ready" to halt her career to have children.

The couple celebrated its one-year wedding anniversary on 4 April - and the Irreplaceable hitmaker, who will launch the U.S. leg of her I Am... world tour on 21 June, admits she'd eventually like to slow down and build a family with the rapper.

But until then, 27-year-old Beyonce is content living vicariously through her younger sister Solange and playing aunt to her sibling's four-year-old son, Daniel.

She says, "I definitely want one (a child) but I'm not ready for all that. I don't think a person should see that before their time. I fall in love with my nephew every time I see him."