She went back to a family member’s house around lunchtime a week past Sunday and died that evening.

Her 13-year-old son John Paul had found her on the sofa in a lot of distress and called an ambulance, but she could not be saved.

Her sister Darlene McConnell (44) said John Paul and his younger brother Luke (11) had been left devastated by the loss of their mother.

And she claimed a series of failings in the NHS contributed to her sister’s death.

Mrs McConnell said Ms Beavers had called her at 5pm on Saturday, July 25, complaining of numbness in her toes, swollen ankles and leg pains, and she told her to contact NHS 24.

She said they took Ms Beaver’s details and said they would get back to her, and by 2am her condition had deteriorated. Ms Beavers called them again and requested a doctor, but instead they made a hospital appointment for Sunday afternoon.

“She was distressed and she asked for a doctor and they wouldn’t send one,” Mrs McConnell said.

“I was the one who told Debra to phone NHS 24. She put her trust in them and they let her down. They let her whole family down.

“I would never phone them again.”

The next day Ms Beavers was in so much pain she thought she was going to die.

Mrs McConnell claimed when she eventually saw a doctor at the hospital he was “dismissive”.

When she clutched her chest and described her pains, she was told, “Your heart is on the other side”, her sister said.

It is understood Ms Beavers, who was a smoker, was suffering from atherosclerotic coronary artery disease, which causes narrowing of the arteries.

Mrs McConnell added, “We are taking the matter further. We’re completely sickened by the way my sister was treated and they’ll be hearing from our lawyers.

“The boys are devastated and we’re devastated. This has been such a shock.

“I’m not happy with the GPs, not happy with NHS 24. Although they said they were satisfied with their response, we are not satisfied.

“Worst of all was how the hospital treated her. It’s heartbreaking. We’re all hurting and there’s a lot of anger. We will be seeking justice for this.”

A spokeswoman for NHS Fife said she could not comment on individual cases.

She said, “We would like to express our condolences to the family of Ms Beavers. NHS Fife’s duty to uphold patient confidentiality prevents us from making any comment on an individual case.

“We would urge anyone who has a concern about the service provided by NHS Fife to contact our patient relations department on 01592 643355 ext 8557, email patientrelations.fife@nhs.net.”

Eunice Muir, executive nurse director for NHS 24, said, “We are sorry to hear about the death of Ms Beavers and would like to extend our sincere condolences to her family at this time. We can confirm that Ms Beavers contacted NHS 24 and that her onward referral to local services was managed safely and appropriately by NHS 24.

“We would ask the family to contact us if there are any aspects of the case they wish to discuss with us.”