Is there a reason you don't want her on the roof of the coop?
She's very unlikely to actually fly away from you forever, ours fly up trees or on top of the house (9 metres and generally they do the 9 metres vertically then go horizontally onto the apex) or over the pond which is about 30 metres. They are not flying around all the time but obviously they do feel the urge now and then.
I think the clipping should only be the one wing, it DOES make them unbalanced and therefore unable to fly. Both wings clipped can still be used for flight, like during a moult or a juvenile would, it's the unbalancing that prevents flight not the lack of lift generating surface area, which chickens have an abundance of.