The parents of a murdered 12-year-old girl said tonight it was their worst fear to “lose a child so full of life”.

Brendan and Deirdre Davis said they were desperately trying to get their heads around the killing of their daughter Michaela.

Her body was discovered in undergrowth by a man walking along the Royal Canal in west Dublin on Saturday evening.

The grieving couple said their daughter’s death was a needless, awful tragedy and insisted the family was always there for one another.

“This is a heart-wrenching situation,” the distraught parents said.

“A young 12-year-old girl who was full of life has been lost. She was very close to her mum, dad and (teenage) brother Brendan. They were always there for one another.”

A private Mass has been arranged for relatives in the Davis family home tomorrow night.

A funeral service for Michaela will be held on Thursday at St Mochta’s Church where she was christened and celebrated her First Communion and Confirmation.

An 18-year-old appeared in court in Dublin charged with her murder. Jonathan Byrne, from Lohunda Downs in Clonsilla, west Dublin – a few streets from where the dead girl lived – is accused of the killing near the Porterstown Road, a few minutes walk from her home.

Michaela may have been beaten and strangled, sources said.

She was last seen after midnight on Saturday when she told her parents she was going out for a few minutes to meet a friend. Michaela was reported missing at about 2.30am and an extensive search launched.

She had enjoyed her first day of secondary school at Luttrellstown Community College the previous Thursday and her family revealed she had been given her first homework, due to be handed in tomorrow.

“All Michaela’s friends are heartbroken at the moment and cannot get their heads around this tragedy, no more than the rest of the extended family and friends,” Michaela`s family said in a statement.

“The needless loss of a young child, the awful tragedy of a girl barely beginning life.

“This situation is not and never will be about the crime or the perpetrator – it’s about Michaela, and the realisation of a parent’s worst fear to lose a child so full of life.”

Michaela had started Luttrellstown Community College last week, but was said to have been hanging around with older teenagers and some young adults outside of school.

She was also said to have a mature appearance and looked several years older than she was.

Gardai are still investigating if the schoolgirl was being sexually exploited for cigarettes, money or alcohol.

Michaela was reported missing just over two hours after leaving home to meet a friend and a major search operation was launched by gardai.

Large areas around the family home remained sealed off for a third night tonight as the family continued to appeal for privacy and garda forensic officers carried out further searches along the canal.

The young girl’s bike was found separately from her body.

Byrne is due back in court in Dublin at the end of the week for a remand hearing.

Meanwhile, counsellors and psychologists were on hand at the Luttrellstown school to help shocked pupils and teachers come to terms with the girl’s death.

Principal Fionnuala Ni Chaisil said a short service in memory of Michaela was held in the school at lunchtime.

“Everybody is nice and calm and we are helping everyone … the children are our priority,” she said.

“Our thoughts and prayers are with the Davis family.”

Staff from the school put in place a critical incident management team and arranged for guidance counsellors and Vocational Education Committee psychological support staff to come to the school.