I recently started using ground blinds quite a bit, mainly with cats in mind. I design and devise them on the spot so it is not what you are looking for for your son probably. I have two pieces of lightweight synthetic cloth 12 feet long, one in camo and one in white, and a matching piece of netting to go with each. I drape, pin or tie them to brush, trees etc. to improve my "hide" and conceal hand movement. Just my eyes show over the top edge, and I like to look through a screen of limbs, etc. I tend to call thicker cover, or at least sit in it.
Do they work? I've been surprised at how well. In my first use, a coyote trotted up and stood looking at the call and decoy. I was less than 45 degrees off his line of sight, within 25 yards, and he never even glanced my way when I raised the rifle over the top edge of the snow camo and shot him. That was the white cloth draped around alder brush. A bobcat facing me caught the rifle movement but froze to stare for the fatal second or so, at less than 25 yards. That one I used dry ground camo around blackberries and a dark stump in patchy snow.
Seems like the key would be for the ground blind to blend in to whatever is there, like any camo, ghillie etc. A brown ghillie on a snowfield stands out like a neon sign rather than hide you. Same with a ground blind on a plowed field, stubble field, etc.
Does anyone make a small half dome ready made ground blind? I've been thinking of making one that would fold small and light and set up quick. I've only seen a couple of ground blinds and they were full tents.