@meltz...

Do you mean that what you want to do is
a) Photograph (or otherwise acquire) some skin textures and apply them to existing character texture templates? or..
b) Create a copy of your wife's head?

From your original post I'd suspect the former (a).

Alas, I can't really help you, since I'm no expert in the area of creating textures, but  I posted so as to try to clear up a posible source of confusion

Cheers,
Diolma