Munni (18), who was found missing from her room along with another inmate Pooja (20) on December 9, was traced from Kasaar district of Assam by the police, SP Vivek Sharma said.
The team first produced her before Kasaar's district child welfare committee and is now on its way bringing her back to Rohtak, he said.
"Munni, during preliminary interrogation, has disclosed that she had gone out of the shelter house on her own as she wished to get married and live an independent life," Sharma said, adding that the the CBI has been informed about the development.
Sharma said ten police teams had been conducting raids at various places in Delhi, UP, Bihar and Assam simultaneously for last ten days to locate her as she was one of the key witnesses in Apna Ghar case being probed by the CBI.
He said Munni has also given some "vital" information about Pooja, and expressed hope that she too will be "recovered" soon.
The two girls had gone missing from the shelter home on December 9.
A 20-year-old girl was stabbed to death allegedly by a jilted lover in east Delhi this evening, police said.