Star claims that, despite her recent quickie (but not cheap) divorce from Sherlock Holmes director Guy Ritchie, 40, the Material Matron is bent on adding another child to her brood.

A longtime Madge pal tattles to the mag that the pop queen has already signed papers to adopt a four-year-old Malawian girl named Mercy James from the child's grandparents, who are apparently too poor to provide care to the tyke.

"She's hoping to bring the toddler home by early next year," says the snitch.

Mercy's grandfather, Saxon Maunde, is also quoted as saying, "It breaks our hearts to know she will leave us, but adoption is best for her."

Madonna has a daughter from a previous relationship with personal trainer Carlos Leon and a son from her marriage to Ritchie—Lourdes, 12, and Rocco, 8, respectively.

She also finalized her adoption of three-year-old David Banda from Malawi in May of this year.

Star notes that British papers claim Madonna and her supposed boyfriend Alex Rodriguez, 33, will fly to Malawi to pick up Mercy James.