Plus you'd assume that to build momentum with a revolution, you'd need somebody playing the "politician" role, meaning making sure that your side gets the resources, supplies and allies it needs, and putting everybody that can be in the QZ on the same page
Her brother seemed to have these skills and gathered good will from everybody under FEDRA tyranny, so with him becoming a martyr and getting beaten to death by the police state, it begs to reason that she'd inherit his network and folks would be willing to let her in and listen to what she has to say
Her brother's reputation, plus some cunning negociations and social skills, I'm not surprised she'd end up on top.
Now if folks have problem with the acting performance that's another thing altogether. But pretending as if women that don't have military experience can't end up leading revolutions in chaotic times is a lowbrow take. A superficial reading of history or understanding of group social dynamics would be enough to show that the world doesn't work like that