The front elbow should be level or above the barrel when bunting. This allows the hitter to adjust in and out and direct easier. The rear elbow is under the barrel.
I teach younger girls this high front elbow technique too. In my experience, on a bunt, younger girls have a tendency to try to control the bat using the handle instead of the barrel. By keeping that front elbow high, it forces them move the barrel and knees not the handle of the bat to get to the ball.