Britney Spears's renewed determination to regain at least partial custody of her children is thanks to her 17-year old sister, Jamie Lynn Spears who, following the birth of her own daughter, Maddie Briann Aldridge, has become a role model for motherhood to her big sis, OK reports.

Jamie Lynn Spears a role model for motherhood to Britney Spears?

"As happy as she was for all the joy Jamie Lynn is experiencing it was heartwrenching for her to think about her own situation with Sean Preston and Jayden James," a source close to the singer tells OK!. "She knows she has to do whatever the court, her attorneys and her doctors tell her to get the boys back."

Britney is finally ready to participate and play the game. On June 24, the singer,26, went before commissioner Scott Gordon asking for a change in her custody. In a huge win, Gordon granted Brit one overnight a week with her boys.

"Legally, Britney is a child," the insider tells OK!. "How can Kevin possibly give up any custody of his children to someone who is a child herself?"

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By Fabien Montique posted time [ 1:00 PM]