The deceased, a student of class 11, is the daughter of PAC inspector Maan Singh Yadav who is currently posted in Bijnor.
According to the family, she was mentally-ill for past four years and was undergoing treatment.
The incident happened yesterday when the girl's family, on returning home, found her hanging from a ceiling fan in her room. She was alone at home when she allegedly hanged herself, a police spokesperson said.
No suicide note has been found.