The 17-year-old is believed to have murdered the two women after one of them refused permission for him to marry her daughter.
Turkey's state-run news agency Anatolia, reported that teen, named locally as Recep C, took them in a taxi to a quiet woodland area of the regional capital Izmir, where he killed them both.
The alarm is said to have been raised by the daughter after the women failed to return home, prompting police to search the estate they were staying where the discovered bloodstained clothing in a bin.
As of early this afternoon the 15-year-old girl was had still not been told that her mother was dead, the Daily Telegraph understands.
An Irish diplomat has been dispatched from Ankara, to look after the girl, who was not with the women at the time of attack.

The suspect reportedly denied any involvement when first confronted but confessed while being interrogated by police. His father and the taxi driver have also been detained, Anatolia reported.
One of the victims, understood to be from County Down, is said to own property in Kusdasi and spent long spells at the Aegean coast resort, which is visited by thousands by British and Irish tourists every year.
Both women were travelling on Irish passports and are understood not to be British citizens.
South Down MP Margaret Ritchie said she was shocked by the deaths and offered her sympathy to the bereaved families.
"My thoughts are with those involved in this terrible incident," she said.
"And also with their families, who never got the chance to say goodbye to their loved ones. I think all the people of South Down will be saddened by this news."