You have to be careful with that. At a pub that I used to work at a girl did that. The only problem was that she punched the wrong guy. He had to get surgery to fix the damage. She ended up getting sued for assault and battery. She was lucky that there were no criminal charges.I had a similar occurrence brought to my attention many years ago. Two opposite gender peers were in an establishment following a Remembrance Day parade. The male got handsy. The female responded with at least two quick shots to the face, effectively delivered.
This could also lead to a discussion about what constitutes self defence.