Yes, we all hate it. All you can do is clamly state your reasons and hand the choice back to her again. Her choice: you go to the seminar or she goes herself. Either way is fine. Sounds like you did that and handled her attack prety well.
In their mind EVERYTHING you do is an attack. Even being nice and acomidating. All you can do is your best and detach from her as much as you can.
For now, your role in her fantasy play is that of evil villan. She needs that to justify her behavior. Try your best to stay off the stage.
