Court spokesman Allan Parachini stressed afterward that the answers given by Spears and parenting coach Lisa Hacker were not considered testimony.
Spears' behavior was "very businesslike," Parachini said.
The 26-year-old pop princess, wearing a white short-sleeve top and capri pants with pockets down the sides, left court without comment. Federline, in a gray suit, also did not comment as he left.
Months of bizarre behavior by Spears culminated early this year with two hospitalizations. Federline was given full custody of their two little boys, Sean Preston and Jayden James, and Spears' visitation rights were suspended.
But Spears has appeared stable recently, and her visitation rights have been gradually restored. She remains under the conservatorship of her father, James Spears, and her estate is under the conservatorship of her father and an attorney.
A status conference in the custody case is set for July 15.
