I would be concerned with the feet feathering and the possible burrs and thorns...I used to live in southwest Arizona (Ajo to be exact), so I remember how inhospitable that area can be with plants and critters, and I would be a bit concerned about free ranging in the bush with the leg feathers and the fuzzy hairlike quality of the Silkie feathers...however, I never owned a Silkie down there, so I don't know first hand (grandma had a chicken farm of the traditional layers, but no exotics like Silkies).
Not that it couldn't work. I live in the rainy Northwest now, and mud abounds, which isn't friendly for feathered feet either, but it works because I keep my Silkie in special quarters for the queen broodie that she is...and it has an attached grown out pen on deep wood chips.
If she becomes your main chick hatching broody, she will always be in the nest brooding so it might not be such an issue.
Hopefully someone with actual experience will pipe in otherwise find the Arizona thread and ask.
Lady of McCamley
I know what you mean, we've already had to extract a cactus needle from the foot of one of our pullets, it snuck in and I never even noticed her limping or anything. We found it on a routine foot inspection. I do wonder about the feathered feet too. I'd love to have some of the more exotic birds, but I want them to be safe and happy too. I'll go over to the AZ thread and ask around, thanks!