All speculation on the educability of aging Asians aside, you did miss a two-part opportunity. Had you said something to her and then stayed to help her even though you would have missed your bus, you would have had the opportunity to show her that being gay doesn't preclude civil and respectful social behavior, even in the face of her unwitting disrespect of your values.

Don't let it eat you; you've got the rest of your life to rise above the small-mindedness of others. *hugs you*