The remains of 17-year-old Zoe Nelson were found in a field on Sunday.
Today, at police press conference in Motherwell, officers said that neighbours in Easter Cescent, Cambusnethan, Wishaw, had told them they saw flames in the field six hours after Zoe went missing.
Her mother Marieann said: "We are heartbroken at Zoe’s death and devastated by the way she died."
It also emerged Zoe was on a panel-beating course at Motherwell College.
Hugh Logan, principal and chief executive of Motherwell College, said: "Everyone at Motherwell College is shocked to hear this dreadful news. Zoe was a very popular student. Our thoughts are with her family and friends."
The close family gathered at Zoe’s gran’s home in Crindledyke Crescent. She often stayed with her gran Annette Nelson, while her mum Marieann lived doors away. Her aunt Lorna stays nearby and they were all comforting one another.
Police have cordoned off a huge area around the field where the body was found on Sunday afternoon, 24 hours after she went missing from home.
She is understood to have at least 60% burns to her body, which is why it took police more than 12 hours to determine her gender.
Officers were called to the area near Branchalfield Drive in the Cambusnethan area of Wishaw, North Lanarkshire, following the discovery.
Zoe, who lived in Crindledyke Crescent, Newmains, was last seen on Saturday at 5pm.
Her body was found by a resident around 4.20pm on Sunday on the edge of a housing estate.
Shortcuts leading from Cambusnethan Street, the main artery between the village and Newmains, were also taped off today.
As reported in last night’s Evening Times, Zoe was found in a wooded area known as The Monkey Hill.
Police have launched a murder hunt, but said a post-mortem will be carried out to establish the exact cause of death.
Investigating officers are focusing their attention on where Zoe had been and who with after she left home on Saturday until her body was found. It is thought she had been reported missing by her family after vanishing at the weekend.
A neighbour said he last saw Zoe around 3.45pm on Saturday.
Mark Banks, 26, said: "I saw her in the afternoon. There was a guy with her, but I had never seen him before. She was chatting to her mum as a few of them were out in the garden.
"That was the last I saw of her. There wasn’t anything particularly strange or untoward at that time."
Zoe was said to have many friends and was a Rangers fan.
Tributes today began to appear the teenager’s Bebo social networking site, where pals were shocked by what had happened.
One posted by a friend calling her self Jade simply read: "RIP mate, X"
She added later: "OMG your gone babe I can’t believe it man, love u always x x"
Another added: "Can’t believe ur gone chick xxx".