Even after her death on January 14, the Facebook page that had been set up in her honour was defaced by malicious comments and images. The site has since been closed and all the messages on it have been made private.

Phoebe is the daughter of Anne O’Brien Prince and Jeremy Prince, and the sister of Lauren, Tessa, Bridget and Simon. The family was on a short-term relocation in the US from a small village in Co Clare.

Phoebe attended South Hadley High School in Massachusetts where harassment is said to be a major problem. It is reported that several students have already moved to escape the bullying. The school principal Daniel Smith confirmed that Phoebe had been subjected to "insidious, harassing behaviour".

“Some students made mean-spirited comments to Phoebe in school and on the way home from school, but also through texting and social-networking web sites,” Smith wrote in a letter to parents. “This insidious, harassing behaviour knows no bounds.”

School officials said the bullying included disagreements over teen romances at school and the school had recently intervened because of conflicts with other students relating to dating and relationships. The school’s winter cotillion, a highlight of the school year, was due to be held two days after Phoebe's death and she had been invited by a boy to the dance.

Daniel Smith described Phoebe as "a smart, charming – and as is the case with many teenagers – complicated young person who truly valued her close friends and her family".

“We will never know the specific reasons why she chose to take her life,” he added. “However, both local and state police investigations are looking into the role that bullying may have played in her decision.”

Sergeant Robert Whelihan, a spokesman for the South Hadley Police Department said that “in a school with that many kids [700], there are going to be issues,’’

“We are investigating what effects the bullying might have had on the suicide,’’ he said.

Phoebe's family has been left devastated by her death and are seeking privacy. They said:

"Phoebe was gifted with exceptional beauty - but that is not important. She was gifted with a sharp and creative brain - but that is not important. She had impressive artistic talent - but that is not important. What her family and friends from both sides of the Atlantic grieve in is the loss of the incandescent enthusiasm of a life blossoming." (Sources: Boston Globe; Irish Central)