Attempts at reconciliation failed, and when 70-year-old Mrs Jackson died in 2004 her will made no provision for her daughter.Martin Oliver, partner at Wright Hassall solicitors, who represented Mrs Ilott, said in a statement: “Heather is naturally very disappointed with the outcome of the Supreme Court judgment.”She is a hard-working mother who brought a claim to seek reasonable financial provision from her mother’s estate under legislation which has been around for over 80 years.”The Court of Appeal’s award comprised the £143,000 to enable Mrs Ilott to purchase her home, the reasonable costs of the purchase, and payments up to a maximum of £20,000 structured in a way that would allow her to preserve her state benefits.In his judgment Lord Hughes said that the original decision had been correct because the District Judge had already taken into account the impact on Mrs Ilott’s benefits. The decision had been overturned because Court of Appeal judges incorrectly said that the cash award could reduce her entitlement to these. Lawyers said the decision would make it more difficult for children to claim against a parent’s will.Scott Taylor, of law firm Barlow Robbins, said: “This judgment has potentially helped to stem the floodgates for claims by adult children who feel disappointed with the level of provision made for them in a will and has confirmed that only adult children who can demonstrate particularly straitened financial circumstances are likely to succeed.” The Blue Cross, the Royal Society for the Protection of Birds and the Royal Society for the Prevention of Cruelty to Animals argued that the appeal judges “fell into error” when deciding to increase the maintenance payout.The previous judgment said that donations left to charities should be seen as a “windfall” and and that they would have to demonstrate their need for the money outweighed the needs of disinherited family members. Mrs Ilott, from Great Munden, Hertfordshire, made an application under the Inheritance (Provision for Family and Dependants) Act 1975 for “reasonable financial provision” from her mother’s estate.The Act confers the right on a child of a deceased parent to apply for an order if a will does not make reasonable provision for their maintenance.It is the first time an appeal under the 1975 Act has reached the Supreme Court.The law is normally used to benefit children or dependent relatives. This case is unusual because Mrs Ilott was an adult and financially independent from her mother when she made the claim.A panel of seven Supreme Court justices, headed by president Lord Neuberger, restored the order made by a district judge in 2007 that the sum should be £50,000.In the judgment Lord Hughes said that not enough weight had been given to Mrs Jackson’s wishes and that the good works the charities would do with the money added weight to their claim. A six-figure award to a woman who was left out of her estranged mother’s will has been overturned by the Supreme Court after three charities appealed the decision. Melita Jackson left the majority of her £486,000 estate to three animal charities, but her estranged adult daughter Heather Ilott made a claim against the estate, arguing that her mother had not made provision for her. An original settlement of £50,000 made by a district judge was appealed by Mrs Ilott, who said it was not generous enough. The Court of Appeal ruled that Mrs Ilott should be awarded £160,000, including £143,000 to buy her housing association home. This has now been overturned by the Supreme Court, which restored the original award.The judgment means that adult children are less likely to be able to make a successful claim against parents’ estates if they are disinherited. Mrs Ilott has no pension and lives on state benefits. She has five children and lived in a “modest” way, working as a bookkeeper for her actor husband who had “intermittent” work, the judgment said.But it added that significant weight should be given to the wishes set down in a person’s will and that family relationships do not automatically override the needs of charities who would use the money to do good works. He said: “Charities depend heavily on testamentary bequests for their work, which is by definition of public benefit and in many cases will be for demonstrably humanitarian purposes. The property in Hertfordshire which Mrs Ilott was awarded money from her mother’s estate to buyCredit:John Nguyen/JNVisuals “More fundamentally, these charities were the chosen beneficiaries of the deceased. They did not have to justify a claim on the basis of need under the 1975 Act, as Mrs Ilott necessarily had to do.”The judges also said that children would be entitled to more if they had had a close relationship with the parent and therefore a greater expectation of receiving something in a will. The judges also said that the law around wills should be clarified to avoid similar cases arising in future. In a separate judgment Lady Hale said: “I have written this judgment only to demonstrate what, in my view, is the unsatisfactory state of the present law, giving as it does no guidance as to the factors to be taken into account in deciding whether an adult child is deserving or undeserving of reasonable maintenance.”I regret that the Law Commission did not reconsider the fundamental principles underlying such claims when last they dealt with this topic in 2011.”Only child Mrs Ilott was rejected by her mother at the age of 17 after she left home without her knowledge or agreement in 1978, to live with her boyfriend Nicholas Ilott, who she later married. A spokesman for the charities said: “We are pleased that the Supreme Court has given welcome reassurance that – save in limited and specific circumstances – the wishes recorded in a person’s will must be respected.”Blue Cross, RSPCA and RSPB and the charitable sector as a whole rely on generous gifts left in wills, without which much of their valuable work could not be done.”This judgment will allow us to continue to honour the wishes of individuals who choose to remember charities in their will.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.