My DH used to say that I always had to be right. It wasn't that I corrected people but that I usually had to have the last word on things. I've worked to cut that out.
My new thing I have to work on is interuppting people when they are talking. I find that I do that quite a bit (and he's pointed it out). Mostly I think it's because I'm afraid I'll forget what I want to say by the time they finish or that when someone says something and it makes me think of something and I just say it right then.
I think the OP should point out the problem to her friend. She may be taken aback by it, but when she stops to think about it, she'll realize that the OP was right and hopefully thank her and work on changing.