I would not let her fears dictate the things that you can and can't do. I would not let it degenerate into and endless debate. I would not validate any of her emotions that I did not want to reinforce
I would also understand that this could be about control of the relationship. Can she make you do what she wants you to do? Will you validate her fears with a repsonse, any repsonse? I'd also understand that it didn't necessarily make her a bad person overall. Just one little area that could be improved in order to be capable of a more fair and mutually productive relationship.
I'd try to explain that she had to give me more than just an emotional response, a predicatable reaction. I'd explain that I'd be open to constructive criticism, with the emphasis on constructive. If I had to I'd tell her that she wasn’t really helping me, she wasn’t giving me anything I hadn’t already considered.