Chickens will often keep a turkey company. If you only have a turkey though I would recommend getting another. I had one Tom for a while and he did fine with our chickens.
I found a double shelled egg from my hens too. Though it is extremely rare, it is perfectly fine for the hen to lay it. This occurs when a hen has formed an egg and is ready to lay it but for some reason the egg gets pushed back inside the chicken. This makes it’s body think this is a new egg...