A 13-year-old girl with meningitis died after paramedics took two hours to get her to hospital.
Schoolgirl Stephanie Sanpher collapsed after staying off school with a sore throat.
Her desperate mum Joanne, 36, saw red marks on her body and called an ambulance when she started to vomit.
Four minutes later, a rapid response car arrived at their home in Dersingham, Norfolk, - but an ambulance did not turn up until 84 minutes after the 999 call.
Joanne said that by the time the ambulance arrived, Stephanie, who had epilepsy, was critically ill and medics at hospital could not save her.
She was transferred to Addenbrooke's Hospital in Cambridge by the Children's Acute Transport Service (CATS) from Great Ormond Street Hospital but she died four days later.
Joanne told her local paper: "They didn't help her in time and that left her brain damaged. The hospital did a great job, but it was too late by the time she got to the hospital, she was already brain damaged."
An East of England Ambulance Service Trust (EEAST) spokesman confirmed it had a call from Stephanie's mother at 12:07pm on January 31 but said it hadn't received a formal complaint from her.
Dr Anthony Marsh, EEAST Chief Executive, said: "We're extremely saddened to hear that Stephanie died following her collapse last Friday, and send the family our condolences.
"Our first paramedic on scene did everything possible we would expect from an initial response, but clearly Stephanie's condition deteriorated and an ambulance should have been with her more quickly for which we apologise.
"The Trust is in the process of recruiting 400 student paramedics and has taken immediate steps to increase ambulance cover in Norfolk.
Stephanie's mum said: "We loved her so much. She was absolutely our world. She was the most kind and understanding girl.
"She never judged anybody, was just an angel and no trouble. She loved the TV series Hollyoaks and the band, One Direction.
"She was one of those girls that everybody loves. She could go into a room full of strangers and they would immediately take to her."
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