10/09/2007 at 04:00 PM EDT
's attorney says the singer has been passing her court-ordered random drug tests.
"She's passed her random drug tests," her lawyer, Sorrell Trope, tells PEOPLE exclusively. "There's been more than one. They came up negative."
Trope said the singer's chances of regaining 50-50 custody of sons Sean Preston, 2, and Jayden James, 1, are "good, based on the overall circumstances of the case."
A spokesperson for the court would not comment on the drug tests. Kevin Federline
's lawyer Mark Vincent Kaplan was not immediately available for comment.
As far as working with her court-mandated parenting coach, Trope stated, "As far as I know, there have been no complaints."
Last month, Los Angeles Superior Court Commissioner Scott Gordon ruled that Spears is a "habitual, frequent and continuous" user of alcohol and controlled substances, and ordered her to undergo twice-weekly random testing.
Two weeks later, she was temporarily stripped of custody,
and her ex-husband, Kevin Federline
, retains physical custody of the boys for now.
On Oct. 3, Spears was granted monitored visitation rights
with her sons, and must complete a litany of orders by the next hearing date of Oct. 26.
Meanwhile, the arraignment in her driving-related misdemeanors case was postponed until Oct. 25.
However, Commissioner Rebecca Omens ordered Spears be booked, which includes being photographed and fingerprinted, at a police station before that date.