Kirsty, of Pitsea, Essex, suffered from 14 complex medical conditions including arthritis, asthma, growth failure, and impaired kidney function among many others. She was admitted to the Basildon Hospital, Essex, suffering from coughing and shortness of breath in August 2003.
Speaking at the inquest, consultant Stephen Wade, said his decision not to send her to the intensive care unit the night before was a error of judgement that contributed to her death.
Kirsty was treated with two doses of frusemide throughout the night to try and cure the shortness of breath, but her condition worsened. She had responded well to the medicine on previous occasions when she came into hospital suffering the same symptoms.
Dr Raghavendra Gangawahi, who was the doctor on duty that night, told the inquest he did not send Kirsty straight to intensive care because he wanted to wait and see if the frusemide worked.
Dr Gangawahi had three phone conversations that night with Dr Wade, who was the on-call consultant and had cared for Kirsty previously.
He advised Dr Gangawahi not to send her to intensive care and to give her a third dose of frusemide.
Kirsty's condition deteriorated and at about 6.30am she was sent to intensive care. At 7am, Kirsty had suffered a cardiac arrest and medics tried for 40 minutes to resuscitate her. She died of pulmonary edema, a condition where there is an abnormal build-up of fluid in the lungs.
Coroner Tina Harrington said: 'There was a failure to record to seriousness of Kirsty's condition which led to a delay in her transferring her to an appropriate intensive care unit or high dependency unit.
'Notes and medical information was scant. Looking at all of this Kirsty may not have survived this episode. But the delay in getting the sort of treatment from the right kind of doctors contributed to Kirsty's death.'