By Brittany Brady
Ivan Watson and Talia Kayali
(CNN) -- The family of an American tourist killed in Turkey won't tell her two young sons what happened to their mother until their father returns from his tragic search in Istanbul, the woman's parents said Monday.
Sarai Sierra, from Staten Island, New York, had been missing since January 22, when she was supposed to return to the United States. Her father, who had gone to the airport to pick her up, originally thought his daughter had been detained in customs, he said.
After a search that included her husband and brother traveling to Istanbul, Turkish police found Sierra's body Saturday, near ancient stone walls in Istanbul's Sarayburnu district, according to the semi-official Anatolian news agency.
Sierra's sons, ages 9 and 11, were staying with family friends until their father returned.
"That's something we're going to do together as a family, and the father will be speaking to them," Sierra's mother, Betzeida Jiminez, said of talking to the children about their mother.
"It's something that is going to be hard and he (husband Steven Sierra) is going to talk about that when he comes back."
The Sarai Sierra's family said in a news conference Monday that despite the outcome, they were grateful they were offered some closure.
"I thank God that we were able to find her and able to have her with us," Jimenez said.
Absent from the press conference was Sierra's sister.
"My daughter couldn't be here today because she's too broken," Jiminez said. "All she does is cry and she's going through a hard time, her and her sister were very close."
Authorities in Turkey said 21 people had been questioned and nine were arrested in Sierra's disappearance and death. Prosecutors were given court permission to take blood and DNA samples from all those questioned.
Sierra flew alone to Istanbul on January 7. She had gone back to school part-time for her bachelor's degree and planned the trip between semesters, her friend, Magalena Rodriquez told CNN Monday.
"She did a lot of researching about the area, about where she was going to stay, the safest places to go and the time of day to travel," Rodriguez said. Rodriguez had originally planned on traveling with Sierra, but canceled her plans for financial reasons.
Rodriguez, who had last texted with her friend on January 18, described Sierra as witty, with a huge sense of humor.
Police told CNN's sister network CNN Turk that the body of the 33-year-old woman showed signs of stab wounds. However, the police chief of Istanbul, Huseyin Capkin, said Sierra died from a blow to her head. Police suspected she had been killed at a different location than where she had been found.
Sierra was an amateur photographer who had amassed more than 3,000 followers since she joined the photo sharing app Instagram last year. Her husband said she had connected with people through the app and that some followers had even offered Sierra to act as a tour guide during her trip.
Steven Sierra and David Jimenez, Sarai Sierra's brother, traveled to Istanbul to help with the search.
"The last we heard from my wife was Monday morning on the 21st. She had spoken with her sister and the last thing she said was, 'I'm coming home tomorrow,' and she was excited and put a little smiley face at the end of her statement," Sierra told CNN in an interview from Istanbul on January 30.
"You're hoping that she's OK wherever she's at, that she's not hurting, that she's not cold, that she's being fed," Steven Sierra said, choking back tears.
Sarai Sierra's brother said he had been worried about his sister's solo trip.
"We were nervous. Were just like 'always be mindful of what you do, be aware of your surroundings. Don't get too comfortable to the point where you drop your guard down,'" David Jimenez said from Istanbul.
But Jimenez and Sierra's husband said Sarai was determined to complete challenges that she set for herself.
As an example, they described how she competed in a triathlon several years ago, despite being a weak swimmer, and despite the fact that she did not own a bicycle. Instead, Sarai completed the cycling leg of the competition by borrowing a mountain bike from her husband.
Sierra's photo feed while she was in Istanbul displayed images of the city's beautiful skyline and historic landmarks.
She also squeezed in an excursion to Amsterdam in the Netherlands and to Germany, starting January 15.
"She chose to go to Amsterdam for the graffiti," her husband said. "She informed me as far as how her time was out there. And she also had a tour guide that was helping her out there as well, who I know about and who I've spoken with personally."
Sierra returned to Istanbul on January 19. Three days later, she went missing.
Sierra had rebooked her flight to arrive back early, on January 22, in part to surprise her young sons.
Days before her scheduled trip home, Sierra spoke with her father, Dennis Jimenez, via Skype to remind him of her flight number and arrival time.
When Dennis Jimenez went to the Newark, New Jersey, airport to pick Sierra up, she didn't show, he said.
The airline told him she had never checked in for the flight.
"She kept in contact with us all the time," Sierra's mother said. "And then not to hear from her? It's not like her."
After the tourist went missing, Turkish police released a surveillance camera video of her at a shopping mall in Istanbul, flipping through her iPad.
The scenes from January 20 are the last known images of her.
The manager of the small private hotel where Sierra was staying reported last seeing her the day the surveillance video was shot. That was a Sunday.
Her Skype account, which she avidly used, went silent a day later. A day after that, she was not on her flight home.
The time she last talked with her family, Sierra was planning on January 21 to see the Galata Bridge and visit the Asian side of Istanbul, her husband said.
The former capital of the Byzantine and East Roman empires straddles the dividing line between the continents of Europe and Asia.
After Sierra's family raised the alarm that she was missing, some of her belongings -- including her passport and medical cards -- were found in her room in Istanbul, though her iPhone and iPad were not there, according to her husband.
Since Sierra's disappearance, Turkish police detained a Turkish man she had been in contact with, identified only by the first name Talan, according to CNN Turk.