The investigation has revealed Sierra had left her passport, clothes, phone chargers and medical cards in her room at a hostel in Beyoglu, Turkey.
"It was her first time outside of the United States, and every day while she was there she pretty much kept in contact with us, letting us know what she was up to, where she was going, whether it be through texting or whether it be through video chat, she was touching base with us," Steven Sierra told ABC News last week.
The U.S. State Department said Sunday it is in contact with Sierra's family and is providing consular assistance.
"Out of respect for the family's privacy, we have no further comment," the State Department said in a statement. "We thank the Turkish government for all their efforts to locate Mrs. Sierra and we will remain in close contact with them as they continue their investigation."
Sierra's family also thanked the Turkish people for posting their daughters picture and helping with the search.
"I thank god that we were able to find her and that we're able to have her here with us. I just keep asking everyone to continue to pray for us," said Betsy Jimenez.
ABC News' Dana Hughes contributed to this report.