Britney Spears' sons reportedly take "days" to recover after being in her care.
The Toxic singer - who currently shares joint custody of Sean Preston, two, and one-year-old Jayden James with ex-husband Kevin Federline - allegedly doesn't have a set routine for the boys and this makes them
unsettled and upset.
A source told Us Weekly magazine: "Dealing with the kids after they come back from Britney's is really hard on Kevin. It takes him three days to get them back on any type of schedule."
Friends close to Britney - who has been accused of keeping her children up late at night so they won't wake early in the morning - puts her poor parenting skills down to a lack of education.
A source said: "She loves her children so much, but it's like she's never been taught how to properly take care of them. She looks lifeless when she holds them. It's like she doesn't understand the impact of being a mother."
Meanwhile, Britney is set to hire a new lawyer for her bitter custody battle with Kevin.
Attorney Sorrell Trope - who has represented Nicole Kidman and Nicolas Cage - will replace Laura Wasser.
Wasser resigned on Monday (17.09.07) after a court heard Britney's former bodyguard claimed in a written statement the star had taken drugs in front of the boys.
The judge later ruled Britney must undergo twice-weekly drug tests and attend parenting classes to prove she is a suitable mother.
Britney and Kevin were initially granted joint custody of Sean and Jayden when their divorce was finalised in July, but following Britney's erratic behaviour, Kevin is now fighting to become the primary carer.
Britney Performing TOXIC :