Friday Night Funkin' is rated PG, or 13 and over. Anything below that might be too inappropriate for the child, so I'd say 12 and under would be considered too young.
She is the demonic daughter of Daddy Dearest and Mommy Mearest. She is usually seen sitting on top of speakers, bopping her head to the tempo of the music, cheering Boyfriend on and keeping track of combos.