Tetra, there is always an office bully. If you've bad no other problems, just take it as a learning experience. It's absolutely not a reflection of you or your performance. A simple "thank you for pointing that out to me" should suffice. She was wrong for doing it in the center of the office and reflects poorly on her, not you. I had a supervisor who did that to me, frequently. It is hard to deal with but I'm sure your other coworkers don't think the less of YOU but of her, for picking on you.
Good luck dress shopping. You are a miracle. Never forget it