Stranger danger

Chloe, Bailey, Pixy, and Kyle all inherited powers from their parents. But the Ninja have made many enemies over the years and when those enemies find out about their kids, they want their power!
The kids decide to have a nice day at the park, but at their young age, they don't know stranger danger and can barely protect themselves from evil. What will they do?

Chloe: 7 years old, Earth and healing
Bailey: 7 years old, Lightning
Kyle: 8 years old, Ash
Pixy: 5 years old, ice