"An edited version is republished here with permission"
Actually the "she"-s are the edited part.
If I would have only natural light to work with, I would use a big mirror to reflect the sunlight into the room. Than I would play around with the angles and movements to find the 'sunset' and 'sunrise' pattern. Your character has to turn on an internal light soure at 'night' to have some light in the room, when the mirror doesn't reflect any.
But in any case, first you should make a video of the real phenomenon ideally in the same room, and speed it up, so you know what you're aiming for.