Darragh Lyons and Jack Cummins, both aged 18, appeared in Dublin District Court this morning.
Judge Michael Walsh granted them bail subject to strict conditions and adjourned the cases for the directions of the DPP.
The pair are charged with assault causing harm in the incident last week.
Mr Lyons, of Weir View, Glenaulin, Chapelizod, is accused of assaulting the girl, while Mr Cummins of Rossmore Road, Ballyfermot, is charged with assaulting the boy, on December 30.
The girl suffered serious facial injuries and was treated in hospital.
The accused were arrested yesterday morning following searches and charged last night before being brought before the court today.
Garda Ciaran Murray said he arrested Mr Lyons at his home yesterday morning and brought him to a garda station where he made no reply after caution and was handed a copy of the charge sheet.
There was no objection to bail with strict conditions.
Judge Walsh granted bail in Mr Lyons’ own bond of €200. Under conditions, he must observe a curfew between 9pm and 6am and provide gardai with a contact phone number.
Mr Lyons’ solicitor Luke Staines said his client did not have a phone but could provide a number within 48 hours.
He had no previous convictions, Mr Staines said.
Mr Lyons "in fact on a number of occasions tried to hand himself" in but gardai decided not to do that and attended his home and arrested him, Mr Staines said.
The judge did not require Mr Lyons to sign on at a garda station, following defence objections. However, the judge said Mr Lyons should notify the gardai of any change of address within 24 hours.
He granted free legal aid after hearing Mr Lyons was not working and had no assets.
Asked if he undertook to abide by the bail conditions, Mr Lyons replied: "yes."
Detective Garda Michael McNulty said he arrested Mr Cummins for the purpose of charge at a garda station yesterday.
He was charged at 6.41pm and also made no reply after caution. There were again no bail objections subject to conditions.
Judge Walsh granted Mr Cummins bail in his own bond of €200. Under conditions, he is to have no contact directly or indirectly with the alleged victim or any witnesses in the case.
He must also observe a curfew between 9pm and 7am.
Querying the curfew requirement, defence solicitor Lorraine Stephens said Mr Cummins also had no prior convictions and was working full time.
The garda said the curfew would not affect the accused’s work. The incident was alleged to have happened at 9.40pm, he said.
Mr Cummins spoke only to confirm that he would abide by the bail conditions.
He granted free legal aid to Mr Cummins after Ms Stephens said he worked for a tyre company.
Ms Stephens added that Mr Cummins “specifically asked me to indicate to the court that he didn’t cause the injuries to the young woman involved.”
Judge Walsh said in the event of any breaches of the conditions, the gardai should bring the cases back before the court and apply for bail revocation.
Both accused were remanded on bail to April 1, for the directions of the DPP.