Ms Bhoteni is reported as denying that she killed the cow. She received the maximum sentence for the offence.
Killing a cow is illegal in Nepal, the world's only Hindu kingdom.
Ms Bhoteni was sentenced to prison by a district court in Sankhuasabha district some 500km (310 miles) north-west of the capital, Kathmandu.
According to a report in the Kantipur newspaper, she is not a Hindu.
While killing a cow is illegal, it is not an offence against the law to eat meat from a cow.
Another man charged in the same case has fled and police are searching for him, Kantipur newspaper said.