LOL because my son is a graphic artist and everyone in his Fine Arts drawing classes laughed at him too. The prof said, "Dont worry Pete, just draw stick men but make sure the arms match"."
I dont know about pigeons but I had some white doves for awhile living with me so they're probably the same?
They loved the bottom and walking around the room pecking all the time.
If I'm not mistaken she's going to want to be pecking the floor eating? But the pigeon people can tell you better than I can.
I'd go as WIDE as possible. Can you go about 6 ft wide? Side to side? Unless it's just for sleeping.
And if she's going to be in it alot during the day maybe you could rig up some kind of removable roof for sunlight?
Like some rabbit hutches have an extension of caging with no roof so they can go in and out of the sun. Attached to the house part.