The woman’s husband and their son were treated for burns following the blaze at The Plantation in West Park Road, Newchapel, Surrey, during the early hours of this morning.
The privately-owned site, used by members of the Showmen’s Guild of Great Britain - travelling showmen who make their livelihoods through funfairs - was in mourning today following news of the deaths, Guild president David Wallis said.
The 70-year-old said he knew of the family and that the man and woman had been married for “quite some time”.
He said he believed that the children who died were aged one and five, and that the couple’s 10-year-old son was in hospital being treated for burns.
He said: “It’s a terrible thing and all the members of the Guild throughout the country send their condolences out to the family.”
Mr Wallis said the Guild’s benevolent fund would take care of the financial side of things and that two representatives were on their way to the site to help in any way they could.
He added that he had received phone calls from members across the country offering help.
He said: “What can you do when there are children involved?
“We are a travelling fairground community, a regulated body and very well organised and accepted throughout the country.
“We are quite a close community and the families living on the site are all very close and will be looking after those affected.”
Three crews from Surrey Fire and Rescue Service were called to the blaze at 1.37am.
A fire service spokesman said: “Sadly, two children and one woman have died.
“A man and another child were also treated for burn injuries at the scene and the child has since been taken to East Surrey Hospital.
“Surrey Fire and Rescue Service and Surrey Police are carrying out a joint investigation and our thoughts are with the family and friends of those involved at this tragic time.”
Surrey Police said units were at the scene, which remains cordoned off while inquiries are carried out into the cause of the fire.
Police guards stood at entrances to the mobile home site, which is set beside a busy main road.
Two fire engines also remained at the scene as officers stood blocking a public footpath running alongside the site.
A Tandridge District Council spokesman confirmed that the site was privately owned and had been operating on the land for more than 20 years.
He said: “Tandridge District Council is aware of the tragic fire at The Plantation early this morning in which an adult and two children sadly lost their lives.
“We would express our sympathies to other members of the family.
“Tandridge District Council has no role in the management of the site, which is in private ownership.
“We understand that the fire and police services are currently investigating the circumstances of the fire.
“The council has no direct involvement in this investigation but will assist if our services are required in any way.”