"Cowshed Cinderella", Eirian Davies, who won £1.3m against her aging parents last year, has had the payout slashed to just £500,000 by the Court of Appeal.

The 47-year-old sued her mum and dad, claiming they promised her she would ultimately step into their shoes and take over the family's thriving dairy farm.

Miss Davies spent a large part of 25 years milking the cows on Henllan Farm, Whitland, and tending its herd of pedigree Holstein cows.

She said she missed out on going to Young Farmers' Club dances with her two sisters as a teenager because she had to "stay at home with a muck fork".

Her parents, Tegwyn and Mary Davies, now in their 70s, denied they had treated her unfairly but were ordered to pay her £1.3 million by a judge.

Today, however, three senior judges in London ruled that was far too generous - and slashed Miss Davies' award to £500,000.

And Lords Justice Lewison, sitting with Lords Justice Patten and Underhill, gave her 12 months to leave the farm where she grew up.

After the court heard the farm had been "in lockdown" due to a TB outbreak, her parents were given time to come up with the cash they now owe their daughter.

A judge ruled two years ago that Miss Davies was due a stake in the 182-acre farm as fair recompense for the the years of low-paid toil she put in.

She had told the court: "They always told me that the farm would be left to me.

"Even on my birthday, when the other girls were having things, they would say - 'you will have the damn lot one day, it will all be yours'," she said.

Her father would regularly warn her "not to kill the goose that lays the golden egg" if she complained about her meagre wages, she added.

She claimed she could have 'made a better life elsewhere', but her parents insisted that she earned a fair income, also receiving free 'bed and board' and other benefits.

Describing her as 'a self-employed herdswoman', they argued she would have done no better financially had she worked away from the farm.

In 2009, Miss Davies, who had a passionate interest in pedigree milking cows, was shown her parents' draft will, which left the lion's share of the farm to her.

However, the couple later made changes to their bequests and proposed placing the farm in trust for the benefit of all three of their daughters equally.

The family feud finally hit court after an "altercation" in the milking parlour in 2012 and Mr and Mrs Davies tried, but failed, to evict their daughter from Henllan Farmhouse.

The Court of Appeal upheld her right to a stake in the farm and, in February last year, Judge Milwyn Jarman QC awarded her £1.3 million.

Attacking the decision, her parents' QC, Simon Fancourt, said the payout was "hugely disproportionate".

It was, argued the barrister, wrongly based on an assumption that Miss Davies legitimately expected to "inherit the whole lot" on her parents' death.

Describing the dispute as "bitter" today, Lord Justice Lewison agreed that the award was over the top and cut it to £500,000.

The legal costs of the case are bound to come to a high, six-figure, sum, further depleting the family fortune.

Mr and Mrs Davies will have to pay the costs of earlier hearings, but their daughter must cover those run up in her parents' successful appeal.