Earlier reports has indicated that the girl had been adversely mentioned as a suspect by the majority of her colleagues when the matter was investigated.
It was also alleged that before her death, the girl had admitted to stealing the cash.
Matungulu deputy sub-county police commander Evans Mose said the body was found dangling from rafts of a toilet at a local school.
The matter was reported to the Tala police station at around 3.40 pm on Wednesday.
He said the girl had been accused of stealing Sh2,500 pocket money from her fellow student.
"The deceased admitted that she stole the said money and had kept it in the dormitory." Mose told the Star by phone on Thursday.
He said the student was told by the teacher to retrieve the money from where she had hidden it during break time and give it to the school's administration.
It is at that time that the deceased is said to have hatched the scheme to end her life.
"The girl was given keys to the dormitory but she failed to return. This prompted the deputy principal to go looking for her. Unfortunately, they found the girl's body dangling from the roof of a toilet inside the dormitory building," Mose said.
Police moved the body to Kangundo level four hospital mortuary, awaiting postmortem.
Medics transplant pig heart into dying man