She has a "10-day rotation" of office attire. Most women do well to get through an entire week without having to repeat, and that tends to be maintained by constantly replacing things as they start to show signs of wear.
These women, were they actually interested in acting professionally and as mentors, would have pulled the woman aside, and explained kindly what she needs to do, if her attire were indeed holding her back. Granted, she shouldn't get all off-kilter about overheard gossip, but it's obvious they are not interested in heling her, by the fact they chose to be snide (in an admittedly private conversation) rather than redirecting her choices.
I may want to be the CEO, but if I'm an administrative assistant, it would be stupid and pretentious to start purchasing business suits at Neiman-Marcus. You can look professional, even with a "10-day rotation", without breaking the bank or comlpetely re-doing yourself.
She needs to find a job with a bit less back-stabbing, and a bit more actual mentoring.