This may or may not work. We've hauled up the fence and added a bit of barbed wire across the top. And I do feel mean, especially since she stood on the other side looking hurt and with an expression that suggested she thought I had been her friend, and more, that she had been mine. The thing is she's eating everything, including the trees we planted last spring. I've told her she can come in again in the Autumn when there is lots of tidying up to be done and we need a super efficient grass cutter.
I won't be in the least bit surprised if she's back in the garden in the morning. She spent a long time this afternoon checking the fence for weaknesses, she tried a jump, but couldn't quite gain the height she needed. I have a feeling though that she isn't going to let a bit of silly old fence and some barbed wire put her off!