The 26-year-old singer – who's in the midst of a custody battle over her own kids, Preston, 2, and Jayden, 1 – logged some quality kiddie time Monday, teaching an hour-long dance lesson to a group of six children.
"The class was amazing," Robert Baker, director of the Millennium Dance Complex, tells PEOPLE.
In addition to choreographed routines to vintage Madonna songs "True Blue" and "Material Girl" and "Holiday," Spears – wearing ripped fishnets, red boy-shorts and a blue top – also allowed her pupils to free-style dance.
"She even played age-appropriate games in a circle, pretending to be a choo-choo train," Baker said. "Britney was just amazing with the kids and everyone ended up having a blast. At the end of the hour class, all the kids hugged Britney and she seemed very happy."
Kids 'Thrilled'The kids, aged 4 to 7, were selected from the studio's junior program. "The parents gave their permission," Baker said. "They were thrilled. One parent summed it up: 'It's a once in a lifetime event.'"
Well, maybe not. Spears had so much fun, "She asked to please teach a class tomorrow," said Baker, a longtime Spears friend. "We plan to put together a group of about 20 kids for her."
After the class wrapped up at 7 p.m., Spears – who has rehearsed at Millennium three times since Friday – spent another hour and a half working on a dance routine for her single "Hot as Ice."
"She seems very focused about getting back into her old life," said Baker. "[She's] focusing her energy on creating and dancing."