Tell her what she is doing and that you don't like it. I have a hard time hiding any of my emotions, I say how I feel (with respect to the other person of course, I am not rude to them). Just have a heart to hear with her. She is your friend. Carefully plane out your thoughts and bring them up in conversation. If you stumble on your words like I do. Write her a letter, I love writing letters you can say everything you need to say without interruption, plus you don't forget what you wanted to say.

If that don't work, throw it back at her, most people don't like the taste of their own medicine. Or say to her; have you ever hear the phrase if you don't have anything nice to say then don't say anything at all.

You'll never clear this up unless you bring it to her attention, she probably doesn't know it bothers you.

I hope this wasn't to blunt. Good luck!