
I wasn't sure whether to say anything or not, however I felt so alarmed to think that maybe she did this often, that I very gently and discreetly said something to her to the effect that it was probably not a good idea.
She took it well, thank goodness. I guess I would rather say something politely than to walk away thinking I did nothing to perhaps steer her away from a habit that can have drastic consequences in the future.