Thank you for everyone's lovely words. We're back home, George hasn't left my side since we got back and I have managed to have several good cries. Two cat bowls, two litter trays, two cat beds,....
I still feel in shock. Sunday she took ill, Monday she went in for bloods,... and now I've lost her. If I'd have known on Monday how seriously ill she was I would never have gone away. I feel I let her down so much by not being there. 
They came from the cats protection when they were 10ish. They'd been there 8 months and were desperate for a home but because of their age, their colour (black and white) and the fact they had to be rehomed together, well it was causing problems. There was also the small issue of Daisy hissing at everyone who looked in their cage, I was told she was 'grumpy'.
She wasn't grumpy at all. She was depressed. They'd lived with an old man who had been taken suddenly ill and by all accounts (and their size) they had been spoilt rotten. Daisy was desperately uphappy and scared and fed up, she was not a grumpy nasty cat. I was told when they came home not to expect to see her for a few days as she would most likely hide away.
Did she heck? She came out the basket straight away at the small of warmed wet food. (Her brother on the other hand DID spend the best part of a week hiding). After eating her dinner she did a smelly poo in the litter tray. I liked her confidence and immediately liked her.
And thus my Daisy training began. She could be aloof, stubborn, grumpy even, but god I envied her confidence! She was beautiful and calm, reliable in her habits and ways, and when she graced you with her company she was delightful. She was MY companion and I loved that about her. She sussed pretty quickly everyone else was redundant, it was me who was important, and I loved that self sufficiency. She has none of the neediness and people pleasing habits of her lovely gorgeous brother (who I think read the 'How to be a dog' book instead of the cat version).
She tolerated 'the baby', and as Adam got older (he's 4.5) I think she began to like him even,..... she would sit and let him stroke her as he told her she was beautiful. She would let me bury her head in her coat and tell her she was my favourite Daisy dumpling - I think she understood I needed that from her and she was happy to give it. I think she loved me actually, and to be 'chosen' felt immensely special.s For the past 7 years she has been my night time companion, she has put up with dodgy TV habits (I always joked with her that it was X Factor time as I'm sure her looks indicated I should be watching more BBC4!). She would sit on the back of the sofa night after night when the house had quietened down. The only night she didn't join me was Sunday, so I knew then she was poorly. 
As mentioned there was also the hugely significant factor that she detested my then STBXH. I almost have visions of her helping him pack his bags on that horrible day and thinking 'Thank fuck for that'.
I love my gentle, furry, patient, kind and knowing Daisy.