Thanks for all your help,
She's spent most of the day in the pond, she's splashed around & preened herself - although not quite as lively as the others she has looked OK.
When she's come out of the pond and into the pen tonight she's still very wobbly on her feet and easily falls over.
Brought her back inside, gave her a salt bath - no signs of any more leeches anywhere.
She seemed pretty calm to start with, as though she remembered where she was and that it was safe but then she's started stressing a little bit again. Turned the lights off in there to help her settle down. Put warm towels down but she won't settle on them, seems to be standing up a lot. She keeps standing up straight as if she's trying to push something out but then falls backwards, but soon jumps up so think her underneath may be in pain when she sits down.
Seems to be pooing normal, can hear her eating and drinking but only takes a small bit of food at a time.