Britney Spears's sister, Jamie Lynn, is deeply frustrated that Britney hasn't cleaned up her act since leaving rehab, LIFE & STYLE WEEEKLY reports.

Britney Spears is losing family support

On Aug. 9, the insider says, she called her big sister to tell Britney Spears she’d brought Kevin’s actions upon herself. “Jamie Lynn sobbed, ‘You wanted those babies, and look what you’re doing! I’m glad Kevin’s going to take them!’�

Even worse, Brit’s mom, Lynne Spears, is siding with Kevin in the custody fight, too. “Lynne has already said that if she’s called to testify, she’ll say she believes the boys would be better off with him for now,� says a friend of Brit’s.

Sympathy for the pop star is also wearing thin among hometown pals. “Britney needs to straighten up,� her friend Connie Perkins tells Life & Style. “She needs to stop all this unnecessary behavior and get her life together. Brit needs to stop thinking about herself and start worrying about her babies.�