Former Disney darling Miley Cyrus really wants to make sure her childhood is short-lived. Just last month the 19-year-old Hannah Montana star got engaged to boyfriend Liam Hemsworth. And sources say she's already planning for a pregnancy in the very near future. One insider tells Us Weekly that The Last Song co-stars want to expand their family ASAP. Says the source, "Miley and Liam really want to have a baby quickly." The couple got together back in 2009 while filming the Nicholas Sparks romance. Cyrus isn't alone in her procreating agenda -- the source says 22-year-old Liam is ready to be a dad, especially because his older brother Chris just became a proud pop. For the record, the Thor actor appears to be a bit more baby-ready at age 28. But don't expect anyone to try and talk Cyrus or Hemsworth out of their baby-making plans. The insider adds that even their families have given their blessings. The source adds that the controversial former child star is wise beyond her years, "They are both mature and ready for this. Miley is 19 going on 40." Apparently, they must have missed the infamous salvia-smoking home video.