Britney Spears' sister had a baby.

Jamie Lynn Spears gave birth to a baby girl Thursday morning at a south Mississippi hospital.

A person close to the Spears family confirmed the baby's birth to The Associated Press. The person asked not to be identified because the family had not yet announced the baby's birth.

Spears and her fiancé Casey Aldridge named the baby Maddie Briann, People magazine reported.

"Just the family was there," a source told People. "Everyone is healthy and happy."

According to the magazine, Spears had the baby around around  9:30 a.m. on Thursday at a Mississippi hospital near her Louisiana hometown.

Spears' sister Britney, brother Bryan and dad Jamie flew in on Wednesday to be by her side, People reported. Jamie Lynn's mom Lynne had already been there helping her prepare for the baby.

Spears, 17, who got engaged in March, has kept a lower profile since announcing her pregnancy in December.

Spears' co-star on the TV show "Zoey 101," Erin Sanders, told the magazine earlier this year that she believes Jamie Lynn will be a good mom.

"She is just a very good-hearted and warm person," she told People. "We would always hang out on the set and she is a lot of fun, so I think she's going to be an easygoing, fun mom."

 ehh.....I'd still disown her....