Really sad...
Can you PLEASE tell her to contact either of these two rescues, tell her they have wonderful people and Vets who are very, very experienced with both Liver Shunts and MVD. Sounds like this little guy does have a Liver Shunt or MVD and she should NOT be selling him off like that...He NEEDS special care for his liver issues....
Even if she doesn't want to turn him over to a rescue, they will certainly "guide and help her"
Both of these rescues have a TON of Liver Shunt and MVD experience:
Yorkies Inc. Placement Service RetroDoggy Rescue,Michigan Yorkshire Terrier Rescue,Michigan Maltese Rescue