Thank you both. Unfortunately our current problem is getting her into the house. We have set the cat flap on "in only", but she is staying in the garden. We are trying not to feed her, but we know that in the end we will give in and put her dish in the garden rather than let her go hungry.
Once she's inside the house, we have a strategy.
Interestingly, she doesn't mind the cat carrier, as we always put the two of them in together.
First catch your cat!