The girl, Alexa, traveled with her cousin, Dulce, 19, from Tegucigalpa to Spain Thursday to visit Alexa's mother Wendy, who moved to Madrid for work four years ago, thinkSPAIN reported.
Wendy said the plane her daughter and niece were on landed safely, but when she did not hear from them, she began to worry.
Airport officials told her the girls were being held in a room for illegal immigrants, although their papers were in order -- they had valid passports, return flight tickets and enough money for the duration of their stay, the report said.
After 29 hours, Alexa and Dulce were released.
Dulce said she was "so depressed" after spending more than a day in a tiny room that "all she wanted" was to return to her parents in Honduras.
Wendy has sought help from lawyers to get Alexa residency in Spain, saying there was "there is no way" she would allow her daughter to return to Honduras alone next week.
One of the lawyers, Diana Galindo, says she hopes she can prevent Alexa's deportation.
"Now that she's here, we're going to try to make sure she stays," Galindo said.