Novice, it won't be long before your question will be a moot point, as the other posters have noted, the woman is moving backward most of the time.
Not to confuse the matter, but if you watch the Progressive Backward Changes video of the American Waltz on this site, you will see one of the rare instances in which the woman is stepping forward to initiate a step. It's a nice step, one that we like as a way to move away from traffic on a crowded dance floor, especially if other couples aren't particularly paying attention to the proper line of dance.