The tap half-turn dismount you're talking about is an early drill for giant swing to blind changes on bars. In level 4 it honestly doesn't matter which hand a gymnast takes off.
Many think that for a blind change a righty gymnast should take off their right hand, so that when they want to blind-full they half pirouette the same direction they learned a half pirouette for level 8. However, I am a righty gymnast and take off my left hand and I did all the way back in old level 5 as well. I just learned a half pirouette both ways (though going one way is definitely better than the other).
So to answer your question, it doesn't matter as long has your daughter remembers which way she turns and always practices it that way so she gets in the training to do it that way.