Jamie Lynn Spears, the pregnant 16-year-old sister of pop singer Britney Spears, is engaged to her baby's father, according to People magazine.

The magazine reported on its Web site that Jamie Lynn Spears has been flashing an engagement ring from her 18-year-old fiance, Casey Aldridge, to friends and family in Louisiana and Mississippi.

"She's got an engagement ring," a source close to the family told People. "She's been showing it off, talking about it."

Jamie Lynn Spears confirmed with OK! magazine in December that she was pregnant.

The younger Spears sister stars in the Nickelodeon sitcom "Zoey 101." The cable network said in January that the show would go on with its fourth season despite the controversy caused by their star's pregnancy.

In the interim, Britney Spears has been bitten by the television acting bug, having appeared on Monday's episode of the CBS sitcom "How I Met Your Mother."