Explaining a foul to a player

[bas2456]

Had this situation tonight. Keep in mind this was a girls' sophomore game.

A1 shoots a jumper. B2 is boxing out A2, and doing a nice job of it considering the size difference between the two of them.

The ball caroms off the back of the rim, resulting in a long rebound. A2 jumps straight up to catch the ball. She lands, and then immediately jumps straight up again and shoots. Problem is, B2 is still in box out mode, and moves A2 backwards after she left the ground. I called a shooting foul.

B2 clearly doesn't understand the call. I was debating explaining why I called the foul so she didn't do it again, but never got the chance as she was subbed out after the first free throw.

Do you ever explain fouls, unprovoked, to players if they clearly don't understand what they did wrong? If so, at what level don't you do that anymore?