The Spears family has revealed one last shock for 2007.

Jamie Lynn Spears, the 16-year-old sister of fallen pop star Britney, has revealed that she is three months pregnant.

The teenage Nickelodeon star has sold her story to U.S. OK! magazine, talking with her mother Lynn about her impending motherhood.

Jamie Lynn, who has been living with her 19-year-old boyfriend Casey Aldridge, told OK! that she understands the pressures of being so young and having a baby.

She said, "As soon as I found out for sure from the doctor, I took two weeks to myself where I didn't tell anybody. Only one of my friends knew because I needed to work out what I would do for myself before I let anyone's opinion affect my decision. Then I told my parents and my friends. I was scared, but I had to do what was right for me."

Lynn, who is currently estranged from her eldest daughter, admitted that she wasn't happy about the news of becoming a third-time grandmother. She said, "I didn't believe it because Jamie Lynn's always been so conscientious. She's never late for her curfew. I was in shock. I mean, this is my 16-year-old baby."

"Toxic" singer Britney has two children with her ex-husband Kevin Federline. The star is currently in a bitter custody and is currently an example for Jamie Lynn of how not to parent.

Britney has limited visitation rights with her boys, Sean Preston and Jayden James, and is no closer to regaining custody after missing court dates.

Britney started the year with a shaved head and multiple rehab attempts. She also served her mother with a restraining order against her children, before she lost her own parental rights.