Thank you all for your kind messages and positive vibes - you are all stars
Well I have spoken to the vet and they have managed to do an X-ray. It didn't show anything though, but then they did say if the object is plastic it might not show up anyway.
Her blood test was fine though, apart from showing dehydration. She is on a drip and the vet had just offered her a bowl of water. She said she was still pretty miserable and had backed away from the water which made her think she was still feeling sick.
They are going to keep her on the drip overnight and see how she is in the morning and whether she will eat a little food. She hasn't eaten since yesterday morning which, for Coco, is unheard of.
The vet seems to think it is more likely she has picked up a bug of some sort but if she has not improved by tomorrow they will think about further investigation
Anyway, am trying to keep busy - I will ring this evening to see how she is doing. I have just put all her toys and bedding in the wash and will spend the evening removing all the eyes and any other loose bits, just in case
Please keep those healing thoughts coming for my little bear