Hahah, awesome facial expression and pose, I love how well this is done too. Also, your title for this one is what I've always wondered myself, and never learned Marvel's reasoning or explanation for it.
They could not salvage the y chromosome which is why she is female, after 22 failed attempts at male clones they tried making a female clone. The reason it worked is because she in not a complete clone, this being due to the fact that she has the DNA of a female scientist as well as Wolverine's. In a way she is both his clone and his daughter.