Toni McLachlan, 18, was giving evidence at the High Court in Glasgow at the trial of a 16-year-old boy accused of raping and murdering schoolgirl Alesha MacPhail.
The accused, who cannot be named for legal reasons, denies the charges and has lodged a special defence blaming Ms McLachlan, Alesha’s father’s girlfriend.
Asked if she had anything to do with Alesha’s murder, Ms McLachlan replied: “No.”
She told the court: “I loved her to pieces.”
Alesha was spending the start of her school holidays with her father and grandparents in the house they shared on the Isle of Bute.
The court heard Ms McLachlan and her partner would deal cannabis to the accused, who phoned them in the early hours of the day Alesha was allegedly taken from her bed at her grandparent’s house, where the couple also stayed.
Her body was found in woodland on the island hours after she was reported missing on July 2 last year.
Ms McLachlan said she returned the accused’s call at around 6.30am after being woken up to search for Alesha.
Call logs showed he messaged around 9am that day saying “sorry doesn’t matter” with two laughing crying emojis.
The court heard Ms McLachlan asked him to keep an eye out for Alesha since she had gone missing and he replied: “Oh damn am sure she’s not went too far.”
She said she first had a “bad feeling” about the call and thought it was “dodgy looking” but after the messages this went away.
Questioned on how it felt to be accused of murder, Ms McLachlan said: “Horrible, especially when it is somebody that you do love so much.
“But she knew I loved her and that’s what I’m trying to keep in my head just now.”
She added that she was “sad, hurt and angry”.
The court heard she had been in an on-off relationship with Alesha’s dad for about two years.
In response to questioning from the accused’s lawyer, Brian McConnachie QC, Ms McLachlan denied being jealous of Alesha or threatened by her.
She also denied the suggestion she had been in a sexual relationship with the accused for several months between autumn 2017 and early 2018.
Mr McConnachie suggested she messaged the accused on the night Alesha went missing asking him to meet for a cigarette, they then went to a shed and had sex using a condom she provided, which she denied.
He said she then went into Alesha’s room, took her to the woods where she was found “attacked and brutalised her” and “planted” the accused’s semen from the condom, then murdered her, all of which Ms McLachlan denied.
The court also heard from Jorge Williams, who found Alesha’s body.
Mr Williams, 30, from Bute, said he did not know her but went out to search for her after seeing a Facebook message about her going missing.
He found her in woodland having searched the surrounding areas and phoned the police after finding no pulse, later flagging down a police car and showing officers to her body.
Judge Lord Matthews praised Mr Williams for his actions and said he was “salt of the earth”.
The accused denies raping and murdering Alesha, and attempting to hide evidence.
The case continues.