I'm a righty teaching a lefty how to crochet, and I've taught lefties before, including one girl who was completely single-handed - she practically never used her right hand. Everyone seems to have found a different way to adapt. I've scanned in diagrams and then reversed them - that worked for one person but not for another. Someone else sat opposite me and copied but that didn't seem terribly effective. The single-handed girl ended up having to work her technique out herself because I couldn't crochet without using my right hand at all.
I use my left as much as my right so I've been trying to use the normal crochet methods reversed and it's very awkward. What my pupil & I are trying now is holding the hooks and yarn the usual way, but instead of moving the hook with her right hand, that stays still, and it's the left hand that's doing all the moving. E.g. instead of putting the hook through the stitch, we put the stitch over the hook. That seems to be working. I'm going to spend time practising this method so my pupil can just straight copy me.
I like to have a bit of notice before teaching a lefty to knit or crochet so I can switch my brain over in advance.
Trying to teach a righty & lefty at the same time is mind boggling though.