Emily Jones was randomly attacked by a knife-wielding woman at Queen’s Park in Bolton on Sunday.
She died a short time later, Greater Manchester Police said.
A 30-year-old woman arrested at the scene on suspicion of murder has been detained at a secure facility under the Mental Health Act.
‘Little social butterfly’
Emily’s parents said she was their only child and “the light of our lives”.
“She was always full of joy, love and laughter,” they said.
“Emily had such a cheeky smile and was beautiful inside and out. She had a heart as big as her smile.”
Describing her as a “little social butterfly”, they said Emily had a “passion for the outdoors and loved to play any sport, even when she was wearing her pink sparkly dresses”.
“This random act of violence means that we will never get to see our beautiful little girl grow up into the wonderful young lady she was showing such promise of becoming,” they said.