Currently she gives you choices and you pick; Ultimatums and you cower. You should stop choosing. You can listen to her and then after a pause of a second or two, simply tell her you will not answer her now, you are going to think about what you want to do and you will get back to her when you have made a decision....poof and just like that, you have gently, almost imperceptibly shifted control of the decision and the situation into your hands. NOW, she is waiting on YOU for your decision. Think about it. Works in business and everyday life too.
When you address her, use statements like,
"I have decided" "This is what I'm going to do" "When I have time, I will address this" "Why don't you send me an email or something so I can review it when I have time"
Once you start feeling more in control, you will have less fear, which in turn, will help you feel more in control.
Yes, essentially this is how you seize the "elusive hand"...