Britney "Frantic" Over Sister's Baby News

12/18/2007 11:01 PM PST

Britney "Frantic" Over Sister's Baby News

A source close to Britney Spears tells TMZ that the popwreck is "frantic" over the news that her baby sister, 16-year-old Jamie Lynn, is pregnant.

We're told that before the news hit today, Britney was not aware of her little sis' bun in the oven. Oops ... a Spears did it again.

Recently, Britney was estranged from her mother Lynne, but has spent time with Jamie Lynn. TMZ cameras caught the younger Spears defending her older sister against an angry neighbor last October. Those hormones are a bitch!

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