I suspect nobby that your problem was that the poem was not by Kipling, Winfred Owen, or Tennyson. I find that quoting Kipling is never considered to be in touch with your feminine side.
Red I would say you were not being sexist, but you were being a genderist. Of course, if you had explained to the woman in question that you were French and keeping in practice of surrendering by giving up your seat, she would have apologized, smacked you and sat down.