'Grand plans' are often diversionary - 'I've got the plan to save the world and you will serve me as I do this'.  This is some kind of hero complex and most likely isn't going to get anywhere. It appears from your post that she's dragging a lot of people into this - it might work if she is charismatic, but if everyone else is burning out she'll end up left with nothing when it's time to count the chips.

ACA (AKA ObamaCare) is a public demonstration of just this kind of attitude: We're Congress and the Administration - we say it's a good thing to do, therefore you will do it by our deadlines.  Both your working associates and the political actors are oblivious to costs or practical details - it isn't coming out of their pocket, at least until review time or reelection.

The best thing to do is stand back and watch.  Take care of what you're supposed to be doing, and nothing more. If you and her (as well as others) are in weekly progress meetings with higher level managers, prod her to describe to her managers the demands she's making on her co-workers. They should get a sense of the fact that she has turned into a bull in a china shop.

Things not to do: first, don't try to 'defeat' her plans. People learn by making mistakes, and some companies encourage or even demand experiments with potential for failure.  Maybe this is a good idea, and it's possible she's being cultivated for higher roles.  You might see something in all this you respect, later on.

Second, don't organize or participate in a 'revolt'. If several of the other workers are cooperating to 'bring her down', stay out of it.  Each of you should do what you can and make your own choices, but there is no point in trying to undercut constructive efforts, even if they're misguided.  Ms. Ambitious will have to learn to get what she wants done with limited resources. As do we all.