Thank you to everyone for your kind thoughts.
Bella is much better - thank goodness.
The visit to the Vet last night was a good idea. We managed to get her to eat a bit of special food and then she perked up, as though she had never been sick. A couple of hours of attention and play, a few cuddles and snoozes on family members laps and she went to sleep at 9pm.
She then woke at 3am, went out for her business and then wanted to play. We gave her a little more food (not something we will do normally), and she settle down again around 4am. I heard her crying at around 5am, so got up and took her out. I left Ivan to try and sleep in a little longer and lay down on the couch with Bella.
We must both have then fallen asleep, because I heard the shower start and woke to find that Miss Bella and wriggled up out of her towel, and was asleep tucked under my chin, with her nose under my ear.
She is currently visiting Mom and Dad with Sarah at the cottage and Mom has just phoned to say she is bouncing on their bed, playing with Dad - oh dear - what a spoilt puppy!