I have greatly enjoyed the batshitery on this thread and OPs very droll replies to some of them!
For all those Barbara supporters who think OP should just hand over this land to her, Barbara could have bought the land outright if it meant so much to her. She could even have paid in instalments over the 10 years she has had use of it.
She had warning that she would lose that right as soon as her friend put her house on the market so it can’t have come as a huge surprise that the new owner wanted to take possession of the land they have just bought and paid for.
I assume there are people on here who would be perfectly happy to hand over random chunks of property according to the whim of the barrack room lawyers on mumsnet!
Hope it gets sorted without too much angst OP and happy harvest!