Canine liver cancer

Shelby, my german shepherd/blue healer mix had always been an energetic athletic little girl. She regularly would jump up and 'nose' my hat off my head when I came home. Shelby was always so animated and expressive. Physically, her energy level while playing could only be described as explosive. She turned three years old this spring.
As summer hit I noticed she began to become finicky about her food and her energy level was dropping. Thinking that the heat was bothering her again this year, I set aside time the next weekend to cut her hair (it's incredibly thick and black, so not great for the heat and it takes hours to trim). About halfway through I knew it was more than the heat that was bothering her. Without all that thick fur, it was evident she had lost more weight than any of us had thought.
The next wednesday we took her to the vet, who, after an exam and blood work results, told us she had liver cancer. I was floored, the concept, for me, was inconceivable.
She has lost over twenty percent of her body weight in about three weeks, in spite of the medications and her new high protein diet. The first week on her meds She didn't do much more than sleep and puke (there was some vomiting before, but whether it was the pills or the cancer progressing, I couldn't get her to keep anything down).
The meds are easier on her now, She's eating better, though she's not gaining any weight, and her energy level is up considerably, though not near half what it used to be.
The vet said liver failure is probably no more than three weeks off, the cancer looks to be extremely aggressive. We'll all know more when we see him again next week, but the outlook is grim.
I love my dogs nearly as much as I love my kids. Shelby more than the other one and a half (sorry small dog lovers, a fifteen pound mop ain't a real dog). She imprinted on me when she was a pup and still follows me around most of the time. When she's scared or hurt, she comes to me, she's slept at my feet nearly every night I'm home. Right now, as I sit typing, she's laying on the floor next to my chair. Her ribs are showing, her spine, her hips. and when I look down at her she looks up, smiles that toothy little grin, and thumps her tail on the floor.

So you can put a face to her name, I uploaded her photo to my gallery:
y-o-d-h.deviantart.com/art/She…