I am not near as sweet as Karen, I would just kick this so called friend to the curb and move on. I belonged to a group of 4 of us and the one who always wanted to be in charge was snide and and down right nasty sometimes. I put up with her, because that was just she was. I had done everything with and for this woman for 20 years. The 4 of us went on trip to Arizona and the whole time we were there she was very controlling..................she decided when we would eat, where we would go and always a tension underthe surface. On the way back to the air port in Phoenix, she made the mistake of taiking a pot shot at my daughter..................Boom, it was all over. I did not need this toxic person in my life. If she had probroblems she owned them.
I did not confront her but I just quit talking to her . We all worked together. She is obviously very unhappy in her life and by putting others down she felt like a very important person. You can pick on me, but never on my kids.
I know the pain you feel, I gave the babyshower for this gal's first child etc, how could she go after the juggular. Well I did not care anymore, I was just done with plaing games.
You will have to decided how you want to react but remember you are a good and kind person and your friend has a big, stupid mouth.
Try to keep only positive friends in your life. Ones you can count on and even just one good friedn is better then 50 lousy friends.
Hugs at you