Hilda, your 'baby' sounds a delight. Having worked in rescue for many years it is extremely comforting to know that Dogs Trust are still re-homing sensibly, and waiting till the new year till placing your 'babe' in her new home with her new Mum and Dad.
I must say that having read through all the messages from your first post on asking advice on what sort of dog a cat lover should go for, I would have also said a middle aged greyhound. They make the most amazing house pets and believe it or not, are very 'cat-like' in their behaviour.
Having said that, a Springer/Vizla cross is what you have fallen in love with, and I firmly believe that its the dogs that choose us (however it appears at the time!)
It would be nice to hear in the future how things go and how your babe settles in. Of course, fingers crossed for you and her that the home check is successful.
Wishing you great luck and and as much love as you can cope with from your new addition.