The brutal death of 15-year-old ballet dancer Tallulah Wilson under a train at St Pancras Station has shocked the nation. As a jury today determines how the West Hampstead schoolgirl died, here is the timeline of events that led up to her tragic death in October 2012.

Summer 2011: Tallulah’s maternal grandmother dies. The schoolgirl had confided in her grandmother about alleged bullying at St Marylebone Church of England School. Her mother Sarah said Tallulah was very close to her grandmother and was deeply affected by her death.

Christmas 2011: Tallulah becomes physically unwell with undiagnosed illness that her mother believed to be a chest infection.

January 2012: Tallulah begins GCSE dance classes at The Place school in Euston. Her dance teacher said she was the “most able” of her group.

February 2012: Tallulah is still ill and her mother takes her to the GP. The GP tells her mother that Tallulah is severely depressed, which has caused her to fall ill. She is referred to the Tavistock and Portman Trust in Belsize Lane, Belsize Park.

Consultant child psychiatrist Dr Andy Wiener decides her case is so severe that he will treat her himself as one of the most senior psychotherapists at the trust. Her dance teacher notices a change in Tallulah’s outgoing personality.

April 2012: Tallulah shows a school nurse at St Marylebone recent self-harm wounds, which are so severe they have started to bleed again. Her mother told the inquest at St Pancras Coroner’s Court that the school said it “could no longer keep her safe anymore” and she could not return to school. But Lindsay Anncock, head of inclusive education at St Marylebone, said Tallulah’s mother told her she felt she was unable to keep Tallulah safe on the way to school. Ms Anncock said she replied that the school “wouldn’t be able to fulfil its duty of care” if Tallulah came back.

May 2012: Tallulah has her first appointment with Dr Wiener, who diagnoses her with initially with severe depression. She starts to take anti-depressants. She takes her religious studies GCSE exam at home.

June 2012: 15-year-old Rosie Whitaker, who went to the same dance school as Tallulah, dies under a train. Tallulah becomes obsessed with her death, even though the two never met. Tallulah takes her IT GCSE exam at home.

August 2012: Tallulah gets a B in her religious studies exam, but a D or E in her IT exam, taken a month later. Tallulah asks her mother if she can go to Wiltshire to meet a girl she only knows online and that Dr Weiner said it would be ok. Her mother forbids her to go but says the girl can come to their house. Tallulah argues with her, saying that the girl’s mother won’t allow her to come to London. Dr Weiner said at the inquest that he did not realise that Tallulah did not know the girl in real life.

September 2012: Tallulah moves to independent all-girls St Margaret’s School in Kidderpore Avenue, Hampstead and seems to settle in well. She attends her last appointment with Dr Wiener at the end of the month.

October 1, 2012: Tallulah posts on her online blog that she is about to take an overdose. An online friend rings her mother to tell her and her mother runs upstairs, where she finds Tallulah on the bathroom floor. She admits taking an overdose.

She is rushed to the Royal Free Hospital in Pond Street, Hampstead. She is taken home the next day after a psychiatric assessment. Dr Wiener told the inquest he didn’t consider the overdose to be suicide attempt but an act of self-harm.

October 5, 2012: Tallulah doesn’t attend an appointment with Dr Weiner as she feels tired. Dr Wiener said he regretted that he did not insist on her coming but he did not consider her to be a suicide risk at the time of her death.

Around October 8, 2012: Tallulah’s mother discovers her blog, where she posts images of self-harm and portrays herself as a cocaine-taking anorexic. Her mother contacts the website and has Tallulah’s blog deleted. Senior coroner for north London Mary Hassell said mother and daughter then had “an almighty row”, with Tallulah screaming and pulling her hair.

October 12, 2012: Tallulah goes to school for the last time. Her form tutor said she “seemed great” but a classmate told him that she had been “really hyper”.

October 13, 2012: Tallulah steals her sister’s Oyster card and meets up with a 15-year-old friend she only knows on the internet in secret. Despite them both having blogs where they talk about suicide and self-harm, the two girls don’t talk about these topics.

October 14, 2012: Tallulah argues with her mother after she finds out Tallulah lied about meeting up with her online friend the day before. Tallulah says that her 18,000 followers are the only people who love her for who she is. Her grandfather Reginald Wilson takes her to her GCSE dance class so that mother and daughter can have some time apart.

Her mother notices Tallulah doesn’t have her dance bag with her and she replies, “Mummy I don’t need it today”. Her grandfather drives her to The Place school in Euston and she waves to him from inside the building. He leaves after five minutes.

CCTV captures Tallulah sitting on a bench on a near-empty platform at St Pancras International station at around 9.30am. As a train moves out of the platform, Tallulah walks up to the edge of the platform and jumps onto the tracks. The driver tries to stop the train but said there was no chance he could have stopped the train before it hit her. A post-mortem finds she dies as a cause of severe head injuries.