DNA tests have proved the seven-year-old girl taken from a Roma family in Tallaght on Monday is their daughter.
Speaking in Tallaght, the 18-year-old sister of the girl said that the family are “very happy” at the result of the DNA tests.
She said she would like there to be an investigation into what had happened to her sister.
The family are now planning a party when they are reunited with the young girl.
And a friend of the family spoke briefly this evening outside court to say that the family hope and expect to have the child back tonight.
The girl was dramatically removed from a Roma family's home in Tallaght, Dublin, on Monday after a tip-off to gardai that she did not look like the rest of the family.
The child, who spent two nights in the care of the HSE, will now be reunited with her family.
Tests conducted this afternoon confirmed that she is the biological daughter of the Roma couple with whom she had been living.
The Roma family, who said that she was born in the Coombe Hospital in Dublin in April 2006, have now been vindicated.
The 18-year-old sister of the girl said earlier today her sibling has been "very traumatised" by the experience.
Speaking to reporters before the DNA results were revealed, the teenager said: "She is very traumatised and very confused as well.”
“There was about 20 gardai in here (their house) and social workers. They took her just because she has blue eyes and blonde hair. If you go over to Romania, people - most of them - have blue eyes as well."
Others said the girl - who was physically well at the time of being placed into care - was not the only member of the family with blonde hair.
The Roma couple gave their consent to DNA tests being carried out last night.
They were taken to a garda station where they gave samples through mouth swabs.
The girl was also tested in the presence of HSE officials.
The results were sent immediately to the forensic laboratory at garda headquarters before the results revealed that the girl was related to the Roma family today.
The girl was taken from the house in Tallaght, in south Dublin, on Monday afternoon and placed in the care of the HSE.
The girl's sister said she belonged in the Tallaght house and had been living with them since the day she was born in 2006.
She said the girl attended a local school and had been watching TV on Monday afternoon when around a dozen garda officers and HSE officials arrived.
"Everybody was shocked, even all the children in the house," said a brother-in-law of the young girl.
"She didn't want to go with them. She was asking us, 'Why? Why they take me?"
The journalist was given the information about the girl, who is blonde and has blue eyes, on Facebook.
During a two-hour visit to the house, officers interviewed the two adults about the girl and sought proof that she was their daughter.
They had concerns about the child's identity, and as a result of the interview and their attempts to check out the information given by the adults, they decided after two hours to use emergency powers contained in section 12 of the Child Care Act to take the girl from the family and hand her into the care of the HSE overnight.
The family produced a passport for the girl, but the photo used was of a small child and could not be immediately matched with the girl.
Gardai were also told by the family, who have other children, that the girl was born at the Coombe Hospital in 2006, but preliminary checks could not confirm that.
However, an independent examination by the Irish Independent of the Coombe records yesterday showed that the woman had given birth to a daughter on the day she mentioned in 2006.
At the time of the birth, the parents of the infant did not live in Tallaght, but had another address in Dublin. They have been residing in Tallaght for several years.
The child's first name on the birth record differed from the name used by the girl, but it was accepted that this was not unusual.
Gardai said last night that plans to carry out a more detailed interview with the Roma couple were being put on hold, pending the DNA results.
The garda investigation was launched after another Roma couple, accused of abducting 'Maria', a four-year girl with blond hair and blue eyes, told a Greek court that the child's biological mother had given her to them as a baby because she could not look after her.
DNA tests showed that 'Maria' was not born to the couple, who were arrested after police raided a Roma camp in search of drugs and weapons and found the girl.