There is a mean feral tortie that has invaded my babies space outdoors and she has 3 tiny kittens. There is a gray and black striped one (so adorable) and two that look just like their mother. From what I can see of them (without having my eyes scratched out) they have the exact same marking and both look like torties. Their color variations look to be in the same place. I don't know why they couldn't be twins but have never heard of this.