Stuart Camp told how the princess was pretending to knight another famous entertainer when she accidentally struck Sheeran with a ceremonial sword.
No word on what the suspect was listening to do before the alleged attack.
"I felt like a warrior, but Daddy said I looked like Pippi Longstocking," the 8-year-old says in The Guardian.
"Sometimes you have to use a bit of your imagination."
The blade "could easily have sliced a man’s head in two."