
to you all for your loss. And it is a very real loss. Your poor DD. 
------------------to you all for your loss. And it is a very real loss. Your poor DD.
To answer your question:
Do we really know if the cat suddenly developed a fatal liver disease? Could it have been brewing? I recall, when our Ted was sick, our vet saying that animals are very "stoic", don't like to show weakness...I guess it's a throwback to when they were in the wild and they couldn't be weak...only the strong survive and all that stuff.
So my point is, maybe the cat was developing the liver condition but was trying really hard not to show it until it just couldn't fight it anymore.
The kitty was very lucky to have a Mommy who would do the hard thing to not let the kitty suffer.
-------------------Very sorry to hear about your daughter's cat.
Was it hepatic lipidosis ("fatty liver")? This is common in cats (including diabetic cats) but is treatable with aggressive management. These cats can make a full recovery.
. We just went through this heartbreaking experience with our DD and family right before the holidays, as they had to have their 12 yo lab euthanized, so I truly feel your pain. 
Our 12 year old cat died within weeks of being "off" a bit. An ultrasound showed a large liver tumor that had probably been there for a while but caused no symptoms at all. She suddenly stopped eating and within a week was so sick that we had her euthanized. So, yes, this does happen in is quite common in older cats.
Sorry for your loss...it's very hard.
