Brittany Harris, 25, of West Palm Beach, was arrested after an employee at the concert venue found the children, ages 3 and 5, unattended about 30 minutes before the end of the concert, the South Florida Sun Sentinel reported Monday.
The employee took the children to a deputy working the event.
The employee had seen the children near a car in the parking lot of the Cruzan Amphitheatre about three hours earlier, Harris' police report said.
Harris initially said her cousin had brought her children to the parking lot, but later said she had left them in the car so she could watch the show.
Celebrity Families of 2014 [PHOTOS]