I'm going to criticize my friend's cooking.
Why would you criticize his cooking?
I just don't think she cooks so well.
I can understand that you may not like your friend's cooking, but criticizing her for it doesn't help her to become a better cook. Give her some pointers and support her to learn more about cooking.
Well what if she won't listen to me?
I'm sure she will listen to you, as long as it's constructive criticism.