First question: How did she get up there in the first place?
Second question: At the risk of being mistaken for a rocket scientist, how hard would it be to go back in and open one of those windows?
I got a neighbor’s cat down from a porch roof once just by leaning a plank against it, which the cat eventually used. I have no idea how or why he got up there. It’s just one of those inscrutable things cats do.