Re: What would you do? (Older male teacher with young female student)
I would have addressed it w/ dojocho back when the now adult young woman was a minor, but too late now.
If the dojo overall has a good training environment and a good dojo culture, then trust how you have raised your daughter and also be open with her about your concerns. Unless you have been raising her in a bubble, it is not an issue she will be shocked by although discussing w/ her dad may discomfort her.
If you actually have reservations about the training environment and culture, why are YOU training there?