I would prioritize this lateral move above all else. Execute as quickly as possible. You are currently a problem she needs to solve. You will become an enemy she needs to destroy faster than you think. As soon as she's had time to figure out how to skunk you with minimal blowback to yourself, she'll do it. You getting out from under her in as prompt a manner as possible will burnish your reputation and harm hers; you're going to want to be in a position to give two weeks' notice as quickly as possible because she'll reject it if she can. The clock is ticking down and your peril increases.
I agree - I've got one potential lateral move, and one potential promotion being discussed (without her knowledge). She would likely help me get into a lateral position, but I want to do it quickly and give her less time to influence things. Your point about me being a problem is spot on, I am 100% an issue for her and I need to go smoothly and quickly. I'm doing my job, my team likes me, the peripheral team likes me, and she is burning bridges at a rapid rate but she has operational oversight in the area and upper management (like everywhere) loathes admitting they made a mistake in appointing someone. So not only does she have a good deal of power, the group above her don't want to weigh in too heavily because of the questions that will be asked.