Moments later, a nearby pharmacy declined to give the girl an EpiPen injection without a prescription.
Caroline Sloan tried to take her daughter to Temple Street Hospital, but she died en route.
Her heartbroken mother described Emma as "a beautiful, smart and funny girl" who was "one of a kind".
She told the Herald: "My daughter died on a street corner with a crowd around her.
"I'm so angry I was not given the EpiPen to inject her. I was told to bring Emma to an A&E department. Emma was allergic to nuts and was very careful. How could a peanut kill my child?
"I want to appeal to parents of children with nut allergies to make sure their child always carries an EpiPen with them."
Caroline (40) spoke while surrounded by loved ones at the home of Emma's grandmother Veronica Sloan (82) in Drimnagh.
She said she went to Jimmy Chung's all-you-can-eat self-service restaurant at around 6.30pm on Wednesday with Emma and her sisters Amy (20) and Mia (2), and her own sister Susan for a family meal.
She said: "Emma has always been very careful and would check the ingredients of every chocolate bar and other foods to be sure they didn't contain nuts.
"She had a satay sauce. She thought it was curry sauce because it looked like curry sauce and smelled like curry. I'm not blaming the restaurant because there was a sign reading 'nuts contained' but it wasn't noticed. After a while, Emma began to say, 'I can't breathe, I can't breathe'."
Caroline and her daughters left the restaurant and went around the corner to O'Connell Street. She said she went into the Hamilton Long chemist shop and told a male member of staff that she needed an EpiPen injection for Emma.
Fighting back tears, she said: "He told me I couldn't get it without a prescription. He told me to bring her to an A&E.
"I left and I knew we'd have to run all the way to Temple Street Hospital. But she only got as far as the corner of Abbey Street when she collapsed. She died on the footpath. A doctor was passing and tried to help and put her into the recovery position. Ambulance and fire brigade men worked on her. But she was gone.
"Emma was a very attractive girl and had modelled for her class recently at Our Lady of Mercy Secondary School in Drimnagh. She was due to sit the Junior Cert in June.
"She was a beautiful, smart and funny girl. If I could sum her up in one sentence she was 'one of a kind'. She wanted to be a make-up artist.
"Every day she'd have a different look. She loved boys and music and make-up and clothes. She bought her clothes in places like the vintage shop in Temple Bar. She loved Luke Friend on the X Factor. I bought her two tickets for Christmas for the X Factor Tour."
Caroline related how Emma's toddler sister Mia watched her die on the pavement.
She said: "My daughter Amy held Mia in her arms as Emma died. Mia saw her die."
The family had recently moved into a council house not far from Caroline's mother's home and had all been looking forward to Christmas in their new home.
Caroline said: "I took down the Christmas tree this morning. I'll never celebrate Christmas again."
She said Emma, who also had asthma, had a small number of nut-related episodes in the past and had been taken to Our Lady's Hospital for Sick Children when her lips had swollen up.
The Hamilton Long pharmacy was visited yesterday by the Herald and a member of staff was asked about the incident and the regulations concerning the control of EpiPen sales. A senior member of staff intervened and said staff had been advised by gardai to make no public comment.
Last night, a member of the pharmacy profession in Dublin told this newspaper that regulations prohibit the dispensing of EpiPen injections without a prescription.
It is classed as an S1B drug containing adrenalin and has the potential to do harm. Pharmacists are not allowed to give the injection. Mujahid Najeebhun (29), a security man at Clarkes shoe store at the corner of O'Connell Street and Abbey Street, said: "I was very stressed seeing this happen.
"I saw the girl lying on the ground. She was in the recovery position on the pavement and there was something coming out of her mouth.
"Then people noticed she wasn't breathing. A woman was shouting, 'My daughter is dying! My daughter is dying!' The people saw the fire brigade at the traffic lights and they were shouting at them to hurry up.
"They came and began giving her CPR. I'm so sad that the girl died. I was hoping they would bring her back.
"Everybody in our shop was very disturbed by what happened, especially that it happened at this time of year."
When the Herald visited Jimmy Chung's restaurant, a member of the management showed us the menu listing satay sauce with a sign which read: "Satay Sauce. Nuts Contained."
The manager said the sign had been in the same position for several years. He added: "We did not know any of this had happened. I was taking a break when I saw a crowd in O'Connell Street and I thought someone had been robbed or stabbed.
"I'm very sad to hear that a 14-year-old girl has died. I'm very sorry for the family."
Restaurant owner Tony Shek said later: "We heard nothing about it. The staff are often asked by family members if foods contain nuts. But nothing was mentioned to any staff yesterday."
Children's Minister Frances Fitzgerald has requested that an investigation be conducted into the tragedy.
Emma's family will say their goodbyes at the funeral on Saturday after 12.30pm mass in Church of Our Lady of Good Counsel, Mourne Road followed by cremation at Mount Jerome. They have requested no flowers at her funeral, except from her family, and that donations be made instead to Temple Street Hospital.