She had earlier told the Denpasar District Court that she had a history of drug abuse and rehabilitation attempts.
Police also found MDMA and hashish in a drawer inside the villa, but later decided not to charge Ormsby in relation to those drugs.
Ormsby had not been staying at the villa, but had been given the key by Australian DJ Marco Mazzucco, who was also on holiday in Bali.
Mr Mazzucco had been given the keys by Sydney musician Azaria Byrne, who had rented the villa for three nights, but left early.
Both have denied knowing about any drugs in the villa.
It has been reported the conviction means Ormsby would likely not be allowed to return to Australia.
Mr Ary said she would serve her time then go back to New Zealand.
Ormsby has been in custody for nearly five months so her 10-month sentence could see her back in New Zealand by Christmas.
- with APNZ