What would happen if you just sent a mail, with her cc'ed, rather than sending it to her first for review?
If she won't agree to doing a performance review, make sure you've got all that recorded (email, or at least keep a log of the discussion, dates and times, who was there, summary of what was said and what was agreed).
Would it be worth going back to her boss (initiated by you) or HR? Does your company offer anything like 360 degree reviews and feedback, so you get feedback from everyone you work with, not just your immediate line manager?
It's normal for us to get important mails/documents reviewed by someone else before sending, but no one has time to review and rewrite every single mail - you wouldn't have time to do your own job, and unless there really are specific performance issues, people should be capable of writing professional emails. If there are particular issues, you need specific feedback, and that can be followed up with courses, or just some on-going checks till it's shown you've improved.
I've had a manager who is very good at coming up with stuff like, "That's not good enough," and not giving any details, and it's very frustrating, because you've usually no idea what he's on about. Fortunately though, he wasn't my direct manager, so I could mostly ignore it, which you can't. I would have my CV up to date and out there in your circumstances, in case no other efforts improve things.