First I am so sorry you and your gal are going through this - and it appears you only found us this month. Liver shunt is quite common in Yorkies and there is an easy Bile Acids Test which can be done at both 16 wks old and 6mths old to test the function of the liver. One symptom of course is repetitive UTI;s.
Here is a link to a stickey in our library about help for vet bills:
http://www.yorkietalk.com/forums/sic...vet-bills.html
The GoFundMe area is one that many folks do use with success. You can also network with in your nursing school for donations for help in treating your gal. University of Tennessee is where I would go as well for the surgery. Maybe they might have an option for you for reduced surgery costs for compassionate reasons. I have truly no ideas about if they do or do not.
There is of course selling everything of value you own on Ebay - networking for funds from your family and friends.....
I wish you much luck in raising the funds needed.