I've been working with a lady my same age for about 1 year. I am her superior but she doesn't report to me. We are both responsible for sales but she is directly responsible for a customer base and I manage a product line. After repeated conversations over 4 months of how bad her corporate sales are I finally just gave a report on her lack of urgency and the lack of growth in her customer base. She came back at me with some really strong words saying that I came out of no where with these accusations and how could I treat her like this after all she has done for me? She invited me over a couple of times for dinner and drinks....nothing else. I've decided to back away from the friendship for a while until things cool off. Should I apologize?