Britney Spears: 'Sister's Pregnancy was Mind-Boggling' 8/13/08

Troubled singer Britney Spears has spoken for the first time of her surprise when she found out her younger sister was pregnant - insisting the news was "mind-boggling".

In her first interview for two years, the Toxic hitmaker has told of her delight at becoming an aunt - and also of her shock when she discovered that her 16-year-old sister was having a baby.

Jamie Lynn Spears gave birth to her first daughter, Maddie, with her boyfriend Casey Aldridge in June (08).

And her older sibling - who lost custody of her own two sons in 2007 - was overjoyed to welcome the new baby into the family.

She tells U.S. magazine OK!, "That was special, but it was also strange because she's always been the baby. "And now the baby was having a baby... I was shocked a little bit. It was mind-boggling.

And Spears believes her sister's tot will bring her family closer together: "I’m sure the boys will be like big brothers to Maddie."