A 19-year-old university student died from a brain tumour only two years after feeling faint and 'dizzy' at the dress fitting for her mother's wedding. Catherine O'Connor from Dartford first noticed something was awry with her daughter during a fitting for her upcoming wedding. Ellie Watts, 19, began to become dizzy at the occasion in August 2021 - an incident which was later boiled down to a lack of hydration. 'She was almost swaying and said she felt a bit unsteady and had been getting dizzy,' Catherine told Brain Tumour Research. 'At 5ft 3in, and weighing just eight and a half stone, she was tiny and I thought she probably just needed some water.' Ellie Watts (pictured), 19, first began to feel 'dizzy' and 'unsteady' at the dress fitting for her mother's wedding, which was initially boiled down to dehydration The 'beautiful' teenager died only two years after the incident after it emerged she was suffering hydrocephalus But as the 19-year-old continued to feel dizzy and light-headed in the weeks that followed, her mother took her to the GP. However, when the teenager went for her blood and B12 tests that October, they returned completely normal. Following another appointment in January, 2022, doctors boiled Ellie's continued dizziness and symptoms to a vitamin D deficiency. She was instructed to take an antihistamine and drink more water to aid with her light-headedness. But when Ellie started to experience headaches and violent vomiting 'out of nowhere', she was hurried for further medical tests. It later emerged the teenager had a grade one pilocytic astrocytoma, which is a non-malignant tumour according to the World Health Organisation. Although her tumour was non-cancerous, medical tests discovered Ellie was also suffering from hydrocephalus - a build up of fluid in the brain. Following her diagnosis, the youngster had an seven hour operation to remove the majority of her tumour and was walking - without help - only two days later. In the span of two months, a resilient Ellie had even returned to her job at John Lewis and enrolled on to a criminology course at the University of Greenwich. The teenager also had a grade one pilocytic astrocytoma, which is a non-malignant tumour according to the World Health Organisation Following an initial seven-hour operation, the youngster was up and walking unaided within two hours Later in July 2023, doctors affirmed the teenager's tumour was stable, to the relief of her family. Unfortunately it was only mere weeks later the 19-year-old began to experience headaches and vomiting once more. Her mother, Catherine drove Ellie, who was 'dripping with sweat', directly to A&E. Remembering the tragic day, Catherine recalled her daughter on the verge of passing out and being 'soaked' with sweat. 'I told the doctor what was happening and said, "This is really serious, you have to help her, now,"' she said. 'She literally ran Ellie up to the CT scanner with me in front opening all the doors.' After a couple hours, the mother heard a doctor shout instructing colleagues to get Ellie into resus because of her hydrocephalus. 'I was told we needed to wait three more hours so Ellie could have an MRI scan but I knew she didn't have that long and said I wanted her transferred to King's,' she said. As the ambulance arrived to transfer the 19-year-old to King's College Hospital, Ellie became unstable. 'Just as it was about to leave, Ellie started making strange noises and the driver rushed to get a registrar,' Catherine said. 'Ellie was taken off the ambulance to be stabilised and as soon as she got to resus, they started CPR. 'It took eight minutes to get her back and she never woke up again after that.' Ellie was taken to King's College Hospital for an operation but didn't respond as well as medical staff had hoped. The next morning a scan showed her brain stem had been shoved into her spine, causing 'catastrophic' damage. Five of Ellie's organs were donated and helped others following her death. 'Ellie was pretty special. She was full of fun and just the most amazing person to be around,' Catherine said. 'All the tributes we got following her death spoke about how beautiful she was inside and out, and about her smile and positivity. Ellie was stable for 14-months, until she began to experience vomiting and headaches once again She died in July 2023, after her brain stem was pushed into her spine causing 'catastrophic' damage Over 150 friends and family were present at the youngster's funeral, and have raked in thousands for charity since. The mother raised money for Brain Tumour Research by running the Norfolk Marathon on April 28. 'Ellie's death is a massive loss but she will live on, not just in those people to whom she donated organs but in all those who knew and loved her,' Catherine said. Hugh Adam, from Brain Tumour Research added: 'Ellie's story serves as a stark reminder of the indiscriminate nature of brain tumours, which can affect anyone at any time. 'We're determined to change this, but it's only by working together we will be able to improve treatment options for patients and, ultimately, find a cure. 'Brain tumours kill more children and adults under the age of 40 than any other cancer yet just one per cent of the national spend on cancer research has been allocated to this devastating disease since records began in 2002.'