What does Myrtle Wilson look like?

From the text:

Then I heard footsteps on a stairs, and in a moment the thickish figure of a woman blocked out the light from the office door. She was in the middle thirties, and faintly stout, but she carried her surplus flesh sensuously as some women can. Her face, above a spotted dress of dark blue crepe-de-chine, contained no facet or gleam of beauty, but there was an immediately perceptible vitality about her as if the nerves of her body were continually smouldering.