A Double Celebration Dilemma

A child’s birthday is the most special day of the year, eagerly anticipated by friends and loved ones. For kids, turning another year older is thrilling. Children with separated parents sometimes enjoy the bonus of two celebrations.
Kelsey Frederick, excited to turn 13, looked forward to her two parties. Her parents, Schaffen and Christin, seemed to have no trouble coordinating separate celebrations for her. However, something unexpected occurred on the big day. What could have possibly happened?