A hospital spokesman said:
Basildon and Thurrock University Hospitals NHS Foundation Trust would like to send its condolences to the family of Amie Miller at this difficult time.
The Trust would also like to apologise for failings in the care provided to Amie when she was treated here five years ago.
A number of changes have since been introduced in the treatment of children and adults with neurological illness, including the introduction of more regular observations.
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Showers easing with clear spells overnight. Strong winds easing.
Sunday forecast: Heavy rain is expected for a time with gusty winds, then clearing during the afternoon.
March in the Anglia region has been much drier and sunnier than normal although temperatures have been around average.