Beneath the tattoos, black leather ,and vial of her husband's blood beats, in Angelina Jolie, a maternal heart. Since marrying fellow Oscar winner Billy Bob Thornton in 2000, Jolie has been a hands-on step-mom to Willie, 8, and Harry, 7, his sons from one of his previous four marriages. "She's just natural that way," says her dad, Jon Voight. "She's great with Billy's boys."

Now she and Billy have one of their own. On March 12, Jolie, 26, and Thornton, 46, announced that they had adopted a 7½-month-old Cambodian baby whom they named Maddox. Jolie first visited Cambodia while filming 2001's Lara Croft: Tomb Raider and returned last summer with the U.N., for whom she now serves as a goodwill ambassador. "Last November," the couple said in a statement, "we visited an orphanage in Cambodia and met a little boy we felt a connection to and that we wanted to be our son."

While the pair awaited the usual approvals, the U.S. government halted adoptions from Cambodia amid allegations of baby selling. Only when the ban was lifted for dozens of families earlier this month did Jolie and Thornton take custody of Maddox in Africa, where Jolie is filming the upcoming movie Beyond Borders. The couple, who say they will raise Maddox in the U.S. and Cambodia, confirmed the news after first-time grandpa Voight, 63, blurted it to reporters in L.A. on March 11. A day later he still couldn't contain his joy, telling PEOPLE, "I'm very good at diaper changes!"