oh that is much clearer!
You have more vertical space that it appeared at first. You could put a 3 or 4 inch lip across those nest areas to make them into comfy nest boxes and to keep the litter contained. Do they like those spiky mats? I've always used soft natural material myself.
Tell your fiancée (in due course after the wedding) that this is just the nursery coop. You'll use it to grow on the chicks you will hatch each year, and your big girls will need a much bigger coop to live in (with the new additions joining them)
It need not cost much. A used garden shed from craigslist is perfect, painted up pretty and some scrap wood for roosts and poop board. Plastic crates for nest boxes. Easy!