Jamie Lynn Spears gives birth to baby girl

Britney Spears has become an aunty, after her younger sister Jamie Lynn gave birth to a baby girl.

The baby was named Maddie Briann and weighed 3.49 kilograms, according to a friend of the Spears family, who asked not to be identified because the family had not yet announced the baby's birth.

Spears gave birth at a south Mississippi hospital, but Ellen Brannan from the Southwest Mississippi Regional Medical Centre would not give out any details.

"We understand everybody's interested, but we don't give out information on anyone. Everyone's entitled to their privacy," she said.

Nickelodeon issued a statement about the birth, saying: "We wish her and her family well."

Spears starred in Nickelodeon's Zoey 101 children's TV series.

The Spears family announced in December that 17-year-old Jamie Lynn was pregnant.

The father is Casey Aldridge, a pipe-layer from Liberty, Mississippi.

The couple is not married but announced an engagement several months ago.

The younger Spears lives near Liberty with Aldridge, 19, and has been seen around the small south Mississippi town often as her pregnancy became more apparent.

Her family owns a home across the state line in Kentwood, Louisiana.

Spears announced her pregnancy through an article in OK! Magazine and was expected to receive a large payday for exclusive pictures of the newborn.

Via smh.com.au