Vin, to try to explain as best i can

What does she want the land for?
Control in summary, so she doesn't have anyone coming in the field adjcanent to our house, using the shared laneway, disturbing her peace etc. That itself isn't an unreasonable thing, I wouldn't mind owning it myself. However if it's not an option - then deciding you can no longer live with it isn't a very reasonable reaction in my view.

What benefit is she going to get out of ownership?
See above

How can you correct this?
I can't unless the current owner of the land, decides to sell it - which he stated he has no intention of doing at any price, despite me making him a reasonable offer. There's other options for sure we could move, it's extreme but it's an option - however I don't want to go there as what's to say the next house won't have something else wrong, or even if the new house is right what's to say she might not hate me because in her view i made her move & did not 'save' our current house. You get the idea.

As others have suggested & i agree myself there is an underlying issue(s) either from earlier in our relationship or something from before we met. Her parents divorced when she was a teenager & I wonder if this could be in the mix somewhere. Equally it could be something else from her life she has never discussed with me.

As an update she texted tonight to ask if there was any news, I texted back & told her there was no news, adding I was sorry I couldn't be more help which is true. She has responded by saying ok forget it. I am not going to text back & will just let the dust settle & see where we go.

As a final point thanks to everyone who has replied to me in the last 24hrs, it's meant a lot.

pp