"It's too easy for teenagers to get hold of drugs. Drugs are everywhere and somebody will always know somebody who will sell you some.
"Unfortunately there are websites where people talk openly about their drug habits and which drugs they like and don't like and glorify the effects."
Explaining their daughter rarely drank or went to parties due to suffering Crohn's disease, Mrs Harding, who provides holistic care for drug addicts, and her husband said: "Serena just wanted to be like everybody else her age.
"We believe Serena got out of her depth and gave in to peer pressure.
"Every day we ask ourselves `how can this be?' Serena filled all our hearts; she was so loving and caring and was sometimes wise beyond her almost 17 years.
"The tears we cry everyday are futile because she will never come home again."
Miss Harding, who was studying a fashion and design course in Warrington, Cheshire, took the drug with friends while celebrating her exam results on August 21.
Manchester Crown Court heard she had been encouraged to take it by Michael Millington, 19, who Serena knew well and had a "crush" on. A friend later said she had wanted to impress him.
She was found collapsed and struggling for breath Reddish Vale Park in Stockport, Greater Manchester and died in hospital at 10.50pm, shortly before her 17th birthday.
Police initially arrested four men aged 20, 19, 19 and 18 and a 25-year-old woman over the last summer's tragedy but two of the suspects were released without charge.
Today, Millington received a 12 month suspended sentence and 300 hours unpaid work for his involvement in the incident.
Thomas Donelan, 20, was sentenced to two years at a young offenders intuition for possession and supply of a Class A drug.
Dean Williams, 18, who handed over the money to Donelan for the drugs, received a suspended sentence of six months imprisonment and 250 hours unpaid work.
Sentencing them, Judge Maurice Green called all three "misguided individuals who believed and were part of a culture who believed that taking drugs such as Ecstasy and MDMA is harmless."
"This is a tragic case for all concerned, the greatest tragedy clearly is that resulting from the death of a 16 year old girl, Serena Harding," he said.
"It's impossible to quite understand the devastation that her family must feel as a result of losing that young girl.
"You three now clearly understand form what you've read and heard that these drugs are pernicious, they are not harmless.
"As a result of your involvement a young girl died."
Detective Sergeant Dave Jordan from Stockport CID called the death a "tragic and needless one", saying it was a "stark reminder that drugs are dangerous and can kill people".
