I would stick with it for one more class and just ignore her pushiness. I know breeders like that, and though truthfulness is appreciated, blunt rudeness is not. I recently told a breeder who judges exactly what I thought of her frankness and I think she almost respected me through her intense dislike because for once, someone wasn't sucking up to her and taking her poor manners because she was a judge.
A good excuse is to say something along the lines of 'Ah, she doesn't respond well to that technique.' and tell her she shuts down and that you've had more success with a different way of doing it. That way you're just saying that your dog trains better this way, and she'll be more likely to leave you to it. I had to do something similar in puppy class once with a trainer who was all for dragging my puppy around on a leash instead of a non-training harness and wanted to do a few other things I didn't agree with. When I told her that my pup was still insecure (ten weeks old, lady!), and I was using less invasive techniques (Read

ositive), by the time we graduated my pup was the teacher's pet and she LOVED her, insisting by the end of the class that I 'do something productive with that little dog!'. So if you just show her you're an awesome trainer without being pushy, she might just learn from you that you don't have to be a hardass to get results.
Good luck, sometimes it's hard trying to stand up to a friend and someone you think is better than you, but I can bet you she's done it to someone in her time!