Most farming families would find it difficult to believe that things said to their adult child working on the farm could result in the court awarding that child one third of the net value of the farm, without anyone signing any legal documents to that effect.

Fortunately for the parents in the case of Davies v Davies, on 19 May the Court of Appeal decided that to do so was too much, and dramatically reduced the sum awarded by the High Court last year.

Eirian Davies was the only one of three daughters interested in farming the family's 750 head dairy herd. She had a turbulent relationship with her parents, but she claimed that they had effectively promised her the farm.

In earlier court proceedings it had been found that Eirian had fulfilled the criteria to establish a 'proprietary estoppel'. That is the legal doctrine by which those making representations to another, where the other person relies on them and acts to his detriment, can be prevented from going back on those representations. The Davies case is a rare example of the doctrine operating whilst all those involved are still living. It is more common for such battles to be fought over a deceased's will.

The trial judge found that between 1985 and 2012, Eirian had suffered detriment by working long hours on the farm without full payment and that, had she not worked on the farm, she would have been able to pursue an alternative career with preferable terms and conditions. However, she had not worked on the farm for the whole period. Her working had been interspersed with periods of estrangement from her parents and the farm.

Certain key events could be identified, including an offer to her that the farm would provide a home for life, as a feature of the final period of her returning to work there in 2008; her being led to believe that that she had been a partner in her parents' farming business between 1998 and 2001, when she was not; and an offer that she should be allocated shares in the farming company in 2008, which she was not.

It was found that a value of £350,000 could be placed on these items of 'detriment'. The question was whether it was right of the judge to have awarded her almost a further £1 million for her claimed loss of expectation.

The Court of Appeal found that a number of the elements of expectation had already been included in the £350,000 and that one should not lose sight of the fact that the period in which the expectation had been generated was over just four years, between 2008 and 2012.

This was because in divorce proceedings in 2006, Eirian told the court that she had no expectation of inheriting anything from the family farm. That statement now contradicted the position she was taking against her parents. It was also set against the fact that the Davies had built up their substantial farm from almost nothing over a period of more than 50 years, and had continually re-invested their profits in the business. In contrast, Eirian had contributed nothing. That made the total award of £1.3 million completely disproportionate to the actual loss which had been found. Instead, the Court of Appeal added £150,000 to more easily quantifiable £350,000; a total of £500,000, representing a reduction of over 60%.

The Davies case is a family tragedy. It is a story in which the press have portrayed Eirian as the 'Cowshed Cinderella', forced to work long hours on the family farm whilst her sisters went to parties. The court found the truth to be somewhat different.