Liza Lee's advice was awesome and she is my official go-to person now for handling sticky situations. Unfortunately, by the time she left her comment I had already bumbled my way through the confrontation.
TIMING, PEOPLE. IT'S ALL ABOUT TIMING.
Truth be told, it went very well. I dressed with particular care in the morning so that she would take me seriously. A skirt, a nice top, and really cute Madden Girl red high heels. This lady is 5'10 and I didn't want to have to look up at her. (The blister on my pinky toe by noon was totally worth it.)
I realized as I started to talk to her that I didn't feel intimidated at all. I don't like her, I don't give a shit what she thinks about me, and it's fucked up to call a 7-year-old stupid.
The conversation went something like this.
Me: I have a concern about Estefania that I wanted to discuss with you. She came back from math feeling upset, and she told me that the unit test was too hard and she felt stupid.
Me: I've never observed that with her in the past. Also, she said that you said she is stupid.
Mean Teacher: That never happened.
Me: Well, I thought you would want to know what she told me.
Her denial was so flat and so quick that I knew instantly she really had called the kids stupid.
Anyway, I felt victorious and proud all day because I had done something that was really hard for me to do. And it turns out that I can do it and it wasn't even that difficult. It felt good to be direct and calm.
I have been such a wimp my entire life. But now that I have tasted blood I will be ALL UP IN YOUR FACE if you piss me off. Ha! Kidding! Don't hurt me!
Thanks for all the advice and support, you guys. I hope everyone has a fun weekend.