Thanks everyone for all your kind words. We are all heartbroken that we're going to lose her, she's such a little soul mate and neither of us can imagine coming downstairs in the morning and not being greeted by her crazy charging up and down the house like a little bucking bronco shouting "woowoowoo!" just with the sheer joy of being alive. For me she's the best dog I've ever known.
Zorro has also spent his whole life with her and has been such a nursemaid to her, sleeping outside her crate when she'd had her operation and really looking after her.