A former head girl has been accused of faking the will of her old headmistress in a bid to claim her £4.2million estate.
Maureen Renny, the former head of the independent fee-paying Barn School, left her £1.65milion seven-bed detached house to her family.
However, Leigh Voysey, 42, claims it was left to her to save it from developers.
The sprawling Hill House in Much Hadham, Herts, was the site of The Barn School until 1998.
Ms Voysey started attending the school in 1987, when she was eight.
The mum-of-one claims Mrs Renny had "always favoured her," giving her the best parts in class plays, and that she "reconnected" with her old mentor by chance during the last three years of her life.
She claims the former head asked her to write out a will and organise a friend to sign it on Mrs Renny's behalf in September 2019 over fears it would be sold to developers if left to her blood family.
Ms Voysey claims Mrs Renny knew she "loved" the old schoolhouse as much as she did and decided to leave her everything.
Mrs Renny's cousins and the children of her stepson had stood to inherit it from a 2016 will.
Now Mrs Renny's relatives are fighting Ms Voyse's bid to claim the fortune in London's High Court.
They have accused the former head girl of faking the 2019 will.
Mrs Renny died, aged 82, in January 2020, four months after the new will to leave her £4.2million estate to the former pupil was allegedly made, court documents say.
The 2016 will divide the estate between her cousins Gillian Ayre, Angela Eastwood and Susan Vickers, and the children of her stepson, Thomas and Katherine Renny.
Ms Voysey claims she bonded with her former headteacher after visiting her as a carer and then a friend in 2019.
She claims she wrote her "distant blood relatives" out of her will because she feared they would sell the old schoolhouse to developers.
She claims Mrs Renny asked her to write out the will and have it signed on her behalf because she could not do so herself due to problems with her eyesight.
In papers lodged with the court, she says: "Mrs Renny remembered exactly who I was, even though it was 25 years since I'd left her school.
"Mrs Renny told me that she'd been asking about me during the years since I had left her school.
"The whole experience that day was very touching. I worked one more shift as a carer for Mrs Renny, then visited her as a friend after that.
"After reconnecting in February 2016, I visited Mrs Renny when I could... approximately three to four times a year.
"When I visited Mrs Renny, I would make us both a cup of tea and we would talk about my time when I was at The Barn. We both enjoyed that immensely.
"During one of my visits, she asked me what I thought about The Barn, i.e. Hill House, and I said I loved it.
"Mrs Renny said to me 'I hope it never gets built on'."
Ms Voysey said the former headteacher says she wanted to leave her estate to her in a new will.
In September 2019, Mrs Renny arranged for two of the former head girls' pals to witness a new will because she didn't want her family to know she was doing a new one, it has been claimed.
In the papers, Ms Voysey says: "Mrs Renny asked me to complete the 2019 will and dictated to me what she wanted to be written on it.
"Mrs Renny was unable to sign the will herself as she had problems with her eyesight."
Kate Selway QC, representing Mrs Renny's family, says in the defence to the action: "It is the defendants' case that the 2016 will was the deceased's last true will. The 2019 will is invalid because it was procured by the claimant's fraudulent conduct.
"It is denied that the claimant had any ongoing acquaintance with the deceased after leaving The Barn School.
"It is averred that the only other material time that the deceased and the claimant met was on 19th February 2016 when the claimant was working as a carer... and worked a lunchtime shift looking after the deceased that day.
"The claimant cared for the deceased only once for a few hours over lunchtime on 19th February 2016.
"The claimant undertook no more shifts as a carer for the deceased and never visited the deceased again.
"It is denied that the deceased made the 2019 will or any will leaving her estate to the claimant.
"The alleged events said by the claimant to have taken place...never happened.
"The deceased never signed the 2019 will. The 2019 will was completed in the claimant's handwriting and allegedly witnessed by two friends of the claimant who were not known to the deceased."
The barrister says it was "impossible" for the blank will to have been on the table when Ms Voysey arrived, since Mrs Renny was so frail she could not get out of her chair or even hold a telephone.
Ms Voysey claimed: "I think it was more important to Mrs Renny that she left her estate to me to save The Barn/Hill House and the surrounding land from development rather than leave her estate to her distant blood relatives."
She further claimed the former head told her she had rejected a £10m offer from developers for the land and house.
Ms Selway is also raising an alternative defence to the claim, stating that Mrs Renny lacked the testamentary capacity to execute the will and did not know or approve of its contents, even if it wasn't faked.
She had a stroke in July 2019 and subsequently was recorded in the carer's notes as "talking gibberish," confused about money, vulnerable, delusional and "largely living in the past".
The family also say that, even if she proves her case, Ms Voysey should not be entitled to recover money already distributed from the estate. There is currently £725,000 remaining undistributed.