Maybe she got it as a gift for getting good grades or something?
Are you saying the 12 year olds shouldn't have phones?
Pretty much, yes.
How would you feel as a parent to give your 11 or 12 year old child a $400 phone to play with?
And why in the world would they need such an item? What are they going to do, Instragram their toys or call their BFF's during recess?
It's like the saying "When I was a kid we had boardgames, and we were happy with that."