Britney Spears had no idea!

The news that her sixteen year old sister, Jamie Lynn Spears, was pregnant was as much of a surprise to Britney Spears as to the rest of the world which, considering what has been happening in Britney's life, is no surprise.

If what a family friend has told People is correct, Britney's sister and mother chose to share the news about the pregnancy with OK! magazine without bringing Britney into the loop.

The Gimme More singer was shopping late Tuesday, December 18, night when she was told the news by a photographer.

She replied: "My sister's not pregnant!"

Later she was observed to be driving even more dangerously than she is known to.

"This is going to kill her," says the friend. "In the end, she'll be supportive, but this is a big shock."

Another source told the magazine that advisers for Jamie Lynn, who stars in the comedy television show Zoey 101, have kept her at a distance from her tail spinning older sister.

Interestingly, Jamie's pregnancy was acknowledged through a statement issued by Nickelodeon, producers of Zoey 101.

"Britney doesn't have to listen to anyone now but her sister still does so who knows what people are telling her," says the source. "She has her career now too."

News Copyright © Sawf News. May not be reproduced without explicit written permission