Wilton appealed the sentence in the High Court in March on the grounds that it was manifestly excessive.
Her lawyer, Virginia Pearson, submitted other similar cases that showed Wilton's sentence was out of line with sentences for similar offending.
She also argued Judge Mill hadn't distinguished between the culpability of someone who stole for pleasure or gain, with someone who, "as was the case with Ms Wilton, was driven by a psychological compulsion".
Ms Pearson said there was no basis for Judge Mill's conclusion that it was "clearly premeditated".
"Given that she had a pathological gambling addiction, the logical inference was her offending was opportunistic." She said it was also arguable Wilton had diminished intellectual capacity because of her addiction.
Judge Denis Clifford said there was Court of Appeal authority that offending in order to feed an addiction, for example to alcohol, cannabis or gambling, was not a mitigating factor.
"I do not think the judge can be criticised for the approach he took to Ms Wilton's gambling addiction."
He said it was not opportunistic. "Ms Wilton quite deliberately stole from her father on numerous occasions."
Judge Clifford said the serious aggravating factors were the abuse of trust, the reasonably large amount of money and the impact on Ms Wilton's victims, which included her brother.
Judge Mill had initially proposed a three-and-a-half year imprisonment based on the aggravating factors including her previous convictions for benefit fraud - she fraudulently received $110,000 over five years which she also used for gambling.
He reduced it based on her personal circumstances including her gambling problem, her early guilty plea, and her remorse. Judge Clifford said he would have started the sentence at two years and nine months, in reference to other authorities and similar cases, reducing it based on those circumstances.
He allowed Wilton's appeal and quashed her current sentence, substituting it for a sentence of one year and 10 months' imprisonment. He declined to give her a home detention sentence.