I think she is a mix, but I am not sure how much of a mix they have to be to show that on DNA testing. If you saw the real sire and dam (which I am confused about since she was supposed to be a trade for stud fee right? then why would the breeder have both sire and dam there?). but if those were the parents, then maybe the mix was a generation or two back. So, does the DNA test show if they are 7/8 Yorkie? I don't know the answer to that.
I do not think she is a red leg because a redleg is defined just as much by the pattern of color as the lack of length. See in this picture how the red comes up on the sides
http://www.yorkietalk.com/forums/att...o-cimg1040.jpg You don't see the lack of hair growth of a red leg as a puppy. They do grow hair out more than a short-haired chi, they just don't get the long, to the floor coats of a standard Yorkie. Does your puppy have the reddish color coming from underneath and extending up the sides like the picture? If not, I doubt she is a red leg. Some call dogs red legs if their coat does not grow long, but sometimes those are just wirey coats, another fault.