I'll say it's mostly about how she looks like and sounds like. The shape and complexion of her face and body and her voice. When it comes to psychological qualities, there are not really any nice ones to bring up. Women are just more vulnerable and shy than men and that's about it. If you want to call that femininity, you can so do. Or you can say that being a good mother is feminine like being a good father is masculine but that's kind of redundant. No BS about being nice and honorable as that has nothing to do with gender. So any beautiful woman would do as feminine.
If you wanted me to define masculinity, I would also cite the body and other physical qualities. With the addition of psychological courage and aggression.
I actually wrote the above without reading your question carefully and now that I did, I only hope my answer was not completely inappropriate relative to your question.
