Sarah Clerkson was found dying after being put to bed early by friends because she felt sick.
On her Facebook page, Sarah posted the day before the party: “Fuming honest to god might just end it there and then!”
But her grandparents David and Linda Chapman thought she had ‘turned a corner’ in the weeks before the tragedy.
David, 64, said: “She was bubbling, or in her words ‘buzzing’.
“She was emotionally disturbed but we thought she had turned a corner, we thought things were starting to change for her.
“The last month or two she’s been with her new foster parents, everything had been positive.
“However, to begin with there’d been a problem with her introduction into a new school. She was bullied for about a week.”
He thought the issue had been resolved with the school and ‘blown over’.
“We were lucky to have her,” he added. “She brought so much joy into our lives, we’ve had our hearts ripped out.”
Party host John Moore tried to save Sarah by giving heart massage under instruction from a 999 operator.
Police, then paramedics took over, but she could not be revived.
Sarah, who attended a school in Spennymoor, Co Durham, had gone to a party there at about 8.30pm on Saturday, but was put to bed in a back bedroom after being sick.
John, 16, added: “At about 12.15am on Sunday we went to see how she was. We got no reply and we had to kick the door down.”
She was rushed to the University Hospital of North Durham in the early hours of Sunday but later died.
John said there was drink, but no drugs at the party.
Sarah got on well with other guests, but had mentioned relationship issues and was ‘upset about past experiences’.
Devastated grandmother Linda, 63, said: “It was just like a nightmare when they came to tell me she had died. She touched everybody’s heart.
“She was lovely. She had a heart of gold but she had a lot of emotional issues and family problems.”
Sarah, originally from Sunderland, also made reference to personal issues on Facebook.
David added: “I abhor social networking sites, they cause so much trouble.”
Sarah’s foster family was aware of the issues raised, however, and monitoring her postings.
Thousands of mourners joined Facebook groups paying tribute.
Some suggested she was a victim of on-line bullying, and targeted due to jealousy over her looks.
One friend wrote: “Let the people responsible for the bullying be brought to justice.
“Let them be named and shamed. So they have time to reflect on their actions.
“They now have to live with their conscience…if they have a conscience.”
Another posted: “Breaks my heart to think of this beautiful young girl frightened and scared.”
* For confidential support call the Samaritans in the UK on 08457 90 90 90, visit a local Samaritans branch or click here for details.
* If you’re under 18 and need confidential help call Childline on 0800 1111.
