I am really sorry to hear that. Does she still walk around alot? Thats a good sign. But maybe she is in alot of pain. You should really take the dogs health into cosideration. But it's entirely your familys desicion. I know it's REALLY hard to let a dog go. I had to let my Great Dane/ Basenji mix go a few years ago due to his cancer. He was in unbearable paina nd he didn't even want to walk. Poor baby! He was only three. Make the right choice even if it hurts and good luck.