Just to throw my experience in to the pot!!

I play a right-handed guitar left handed, I.e the chord charts are the same but my hand comes from the opposite side of the neck.

I am currently teaching 2 11 year old boys, but try not to demonstrate too much, because it is too confusing, but obviously I understand righthand fingering so I can help them. I'm not sure how it would work if I teach a leftie, as he/she will be mirror image of what I play!!

If they are total beginners, it is worth checking to see if they 'have' to play leftie in the first place.