Yes, they stay caged day and night until broken. I only let them out briefly 2x a day to clean inside, and to refresh food and water. After 48 hours if they show a lot less broody signs (less puffy, less broody sounds) you can start letting them out to see if they run back to the nest or not. If they do, back in the cage for at least another 12-24 hours.
As a general rule this works. I have a couple that still do the broody sounds or puff a bit when they're broken enough to let back out with the rest. I think over time you'll get to know your individual bird's quirks, if any, and that'll help you figure out when they're broken enough to be let back out.
Roost is fine, as long as she isn't trying to brood on top of it! That's pretty unusual though, so unlikely to be an issue. If it is, just remove the roost.