I agree with everyone here.
I would not let one idiot ruin my fun! Even if they are good friends I would kindly talk to the instructor about what is going on. Maybe see if the instructor can let you know what days this woman is *teaching* class & just skip that one session?

I got it open your own training class & hire the instructor to teach, just dont invite that one woman hehehehehe
ok i know im in a silly mood today