Nadine Marshall gave evidence on the first day of the hearing into the death of 18-year-old Conner Marshall in March 2015.
Attacker David Braddon, from Caerphilly, had mistaken the teenager for his estranged partner’s former boyfriend, before brutally attacking him at Trecco Bay caravan park in Porthcawl.
At the time of the attack, Braddon was under supervision for previous offences. He had previously been convicted of assaulting a police officer and had also been involved in domestic abuse and an animal welfare offence.
He was sentenced to life after being convicted of murder.
Coroner Nadim Bashir said the facts of the killing are undisputed, but he said the issue of Braddon’s probation raised many questions which the inquest will explore.
“Each one of us misses Conner in different ways. I miss the texts he sent every night whether he was away or in the bedroom next door.
“We have lost new memories and watching Conner fulfilling his life and dreams.
“My children have been exposed to the awful real nightmare and as parents we feel we have failed to protect our children from the awfulness of life.
“Our children are remarkable and inspiring and for them, myself and my husband dug to the bottom of our souls to make sure they’re not affected any more than they undoubtedly are.”
The hearing heard that in his police interview, Braddon said he had taken a cocktail of drugs including alcohol, valium and cocaine, describing himself as “off his head”.
Conner was found by a holidaymaker who raised the alarm and he was rushed to hospital.
When paramedics arrived at the scene, they believed Conner had suffered a skull fracture.
They were unable to gauge his temperature as his body was too cold to take a thermometer reading. He was taken to hospital where he was incubated for hyperthermia and taken to the intensive care unit.
His condition deteriorated and he died on March 12, 2015.
Describing her son, Nadine also told the hearing: “Conner attended Welsh medium schools and he was a sweet, blonde, polite little boy. He was inquisitive and had a wicked sense of humour and had many friends who he was loyal and protective of.
“He was very bright and enjoyed the social aspect of school and he enjoyed playing the saxophone, athletics and triathlons.”
The inquest also heard from Kathryn Oakley, a probation service officer at the time of Conner’s murder.
She told the court she looked after around 60 cases, and said the office was often chaotic and short staffed.
She said she worked late and often took on cases from sick colleagues with little information.
She told the court assessments on David Braddon were not properly carried out, and described the workload as overwhelming and lacking consistency.
The inquest continues.