Oh my, those pictures break my heart. I can't imagine how difficult this must be in person. I would definately take her to another vet and try to get a real diagnosis. Lameness is not a diagnosis it is a symptom. Lameness can mean any kind of limping or abnormality of gait. It could be caused by so many different things!
Here is one possibility:
Legg-Calve-Perthes disease
But there are many things that need to be checked out. You can find better information on lameness on some of the equine sites. For instance:
"The most common causes of lameness
The basic processes that cause disease can be remembered by using the acronym DAMNIT:
D: degenerative, developmental
A: allergic, autoimmune
M: metabolic, mechanical
N: neoplastic (tumors), nutritional
I: infectious, inflammatory, immune-mediated, ischemic (low blood flow), iatrogenic (man-made), idiopathic (unknown)
T: traumatic, toxic"
This acronym reminder of causes of lameness was on an equine site but holds true for many species. Best of luck in trying to find teh reason behind your little one's lameness!