Thirteen is often a miserable age to be a human being, period. You don't know what's up or down, your body is changing, everything is changing, and typically, you are easily influenced by peers and others around you, while you're trying to figure out your place in the world.

You are not crazy, you are not wrong, this need not be the death of the marriage. She will not be 13 forever. That, I promise. Can you take her to lunch, away from everyone, and clear the air calmly, say, "I know other people have told you things about me, but I'd like to start this relationship over, just between you and I. I know I'm not your mother, I never aimed to replace her. I am married to your father, and trying my best to be a part of this family. Do you have any questions you want to ask me?" And if she refuses, well, you've made your best effort.