By Todd Quinones

PHILADELPHIA (CBS) – An experimental treatment CHOP might just be able to save a 5 year old’s life.

People in Croatia are rallying behind her and trying to help her family raise the more than $800,000 needed to pay for it.

Just days ago, her parents thought they were out of options.

Five-year-old Nora Situm arrived Thursday evening at Philadelphia International Airport wearing a protective mask.

She’s receiving medical treatment, and two of her doctors made the trip with her and her parents from Croatia.

“This is the only chance that she has. We don’t know how small or big it is, but it’s a chance. In Croatia there’s no more chances,” her mother Jiana Adanasovska said.

The little girl is battling leukemia, but she’s about to undergo a new gene therapy treatment at CHOP that’s only been used on 13 other patients.

“It’s great what your doctors here are doing, because this is [a] big thing for the children with leukemia,” Adanasovska said.

Nora’s journey here started in part on Facebook in Croatia.

Word spread quickly online, and the little girl became a national figure almost overnight as people in the struggling country helped lead a drive to raise the money in just the past few days to pay for the expensive treatment.

One of those people who helped is Croatian singer Tatiana Cameron Tajci. She now performs in the United States and met the family at the airport.

“A lot of people who can’t even afford groceries, and everybody pulled together. I think it’s this desire in people to just believe against all odds, and Nora’s mom has just so much incredible faith that this will all work out,” Tajci said.

Nora’s treatment will take at least several months, if not longer. The good news is the success rate of the 13 others who have received the same treatment has been high.