Between February 2011 and July last year, Wilton used her father's Eftpos card 112 times, withdrawing $21,200 in cash and transferred $60,000 into her own account.
She bought a car with $5000 and the rest of the money was "lost" in pokie machines.
The fraud forced the sale of the elderly man's home.
Lawyer Virginia Pearson told the court her client's offending arose from an addiction to gambling, a problem she had sought help from Care NZ for.
"She has taken steps to address the addiction problem," she said. Ms Pearson argued for home detention for her client.
Judge Mill said the most aggravating feature of the crime was the victim's vulnerability.
Wilton assisted him by driving her father where he needed to go and helping to pay his bills before and after he moved into the resthome, while she lived in his home.
There was no money left, forcing the sale of the home and Wilton's brother has been helping to financially support their father, he said.
"What has happened is you have spent the best part of your father's life savings; security to benefit [him] later in life ... he is forgiving but terribly disappointed ... You considered him a good parent. You have let him down in a terrible way."
Judge Mill said Wilton was a pathological gambler and it was serious offending by her, making imprisonment the only real option for the court.
It was premeditated and a serious breach of trust of a "vulnerable person", the judge said.
"He trusted you implicitly."
Along with the jail term Judge Mill ordered Wilton pay $5000 reparation, with $2500 to be paid by November 23 from the sale of the car she bought with some of the money she stole. She must pay the rest at $10 a week once she is released from prison.
Wilton will also be subject to six months' post release conditions.