That might work...has adjustable legs to accommodate for her sloped floor. Might be a bit of a job getting the frame over the roost. Unless @RoyalChick is a decent sewer...then she could put velcro or other tabs on each corner and hang the canopy cover without the awkward framing.....What about a portable gazebo thingy....
Kinda like this
https://www.walmart.com/ip/Topbuy-7...utdoor-Offset-Tent-w-Carry-Bag-Blue/799008831

That said, her idea of an umbrella would probably work really well....a rain umbrella (larger one) that is smaller than those big patio umbrellas, and tend to be a bit more curved.....as long as the handle doesn't get in the way.