Just realised I didn't update this.
Bea was fine in the end, but needed pigiotherapy twice a day, and spoon feeding mashed bananas, baby milk formula and risks for quite some time. We very nearly lost her, but she pulled through, as did all her lovely babies.
What I learnt was how important it is to get them up and moving- she just wanted to lay down and die, her muscles were wasting and all her considerable weight was on her internal organs. We had to push and shove her and keep her up for 20 mins twice a day. But everyday was easier and now she is fine - hurrah!
Thanks as always to all for advice, good to know you are there. X