I get that. I just think sometimes people don't take the time to analyze their motivations. Sometimes it takes someone telling you that you're being kind of a crappy human being for you take a critical look at your actions. They've been friends for decades, so either this person isn't that bad and this is fairly recent, or this person has always been horrible and the OP is now able to see that. If its the latter, then yeah, drop her like a bad habit, but if it's the former, maybe it's a matter of a wake-up call.