You are asking "What on earth happened to that child? Did you smack her in the head with a baseball bat?
"Did she take a header down the stairs and land flatfaced on the flagstones below?"
"Did her brother finally get fed up with her antics and bop her a good one?"
Nope. Her mother left the screen door open and let a whole HERD of mosquitos inside and one proceeded to feast on her small child's vulnerable forehead.