Two teenagers, who can only be identified as girl X and boy Y, are on trial at Manchester Crown Court accused of murdering Brianna in Culcheth Linear Park near Warrington in Cheshire on 11 February.

The 16-year-old, who was transgender, was stabbed 28 times with a hunting knife in her head, chest, back and neck, the jury has heard.

Weeks earlier on 23 January, girl X sent boy Y a picture of what appear to be red ibuprofen gel tablets and said she "gave her some today that should have been enough to kill her", the court heard.

But girl X said that although Brianna had messaged to say "I feel so bad" and "Oh my god I just threw up and it's the colour of Fanta", she "didn't die", in messages read out by prosecutor Deanna Heer KC.

The court heard girl X also talked about a potential plan to put toilet cleaner and ibuprofen gel in a McDonalds milkshake, and she claimed to have already killed two people, prompting boy Y to say: "You're one kill away from being a serial killer."

Prosecutors have told the jury girl X and boy Y's messages show the defendants were "preoccupied" with torture, murder and death, but there is no evidence they acted on their words before 23 January.

In a statement read to jurors today by junior prosecutor Cheryl Mottram, Brianna's mother Esther Ghey said she remembered one occasion not long before the teenager's death when her daughter was "really sick".

Brianna appeared to be in "real pain" and was "screaming and crying for me to help her," she said, after she got home from work and went into the kitchen to make tea.

"She was in her bedroom rolling around in agony, holding her stomach," Ms Ghey said.

"She was writhing around in pain screaming, 'I think I'm going to die'. It was quite frightening."

Ms Ghey said she thought Brianna might have appendicitis and when she went to get her phone, her daughter said: "Don't' leave me, don't leave me."

She said Brianna was sick all over her bedroom floor, with what appeared to be "grape skins" in the clear liquid, before her condition improved.

Ms Ghey said her daughter "generally stayed in" because of her anxiety but would sometimes walk home with girl X or go to McDonalds with her.

She said Brianna was usually at home by the time she got back from work, adding: "I don't know how often they spent time together, where they went or what they did."

Read more from the trial:
Brianna Ghey's alleged killers 'used code word'
Teens accused of Brianna's murder had 'preoccupation with death'

Ms Ghey told the jury it was "a blur" after police told her about Brianna's death but said her daughter had been going to meet her friend X on the day of her alleged murder.

Jurors were shown a WhatsApp message Brianna sent to her mother which said: "I'm on the bus by myself, I'm scared".

Ms Ghey said she replied "that's all good" as "I was really proud of her".

But she added: "I don't think she ever saw it because it showed as being delivered but it didn't turn blue."

Both defendants, who are aged 16 but were 15 at the time Brianna died, deny murder and blame each other for her death.

The trial continues.