welcome to the forum 11 isn't really that old, I lost one at 12 to cancer but all my others lived to be around 18+. I don't know if the liver regenerates itself or not, just my opinion but I think for that to happen the part of the diseased liver would have to be taken out and hopefully the new gown missing piece would come in healthy and take over for the diseased liver. Livers do regenerate themselves in healthy animals and humans, but first the diseased part has to be removed.
In any event good luck and before doing anything drastic you may want to get a second opinion. Take her to a vet teaching hospital, if anyone can help her they can
he is your friend and protector, he will love you unconditionally, you owe it to him to be worthy of such devotion