Supreme Court Justice John Sulan suspended 46-year-old Rajini Narayan's six-year sentence for setting her husband on fire in December 2008 after confronting him about his affair.
Justice Sulan said the killing was due to "momentary" anger and "muddled" thinking, and that Narayan was truly remorseful for her actions.
"Although it is often said that a suspended sentence is not a sentence at all, it's a real sentence and can be brought into effect if there is a failure to comply with specified conditions," he was quoted as saying by ADelaide Now.
"It is wrong to regard suspended sentences as letting an offender walk free as if he or she has not been punished. It seems (Narayan) has suffered a great deal already," he said.
Justice Margaret Nyland dubbed her actions "rare and exceptional", and therefore deserving of a "merciful approach" in sentencing. Narayan stood trial in the Supreme Court for murder last year.
Narayan denied this, saying her intention was to "circumcise and purify" her husband who had physically and verbally abused her for 22 years.
She said she wanted to "burn a dot on his penis" with petrol and an "angel candle" she had been given by a fortune teller so that he would not leave her for the other woman.
She compared her "bizarre" idea to the Hindu love story of Lord Ram, who proved the purity of his wife Sita with fire after rescuing her from a demon king.
"It would be like circumcision, or just like he placed that red dot on my forehead at the wedding," she said at trial. "It was like I had all the powers of the goddess to save my husband, my lord... it did not occur to me that it was going to be dangerous."
Narayan admitted losing control and throwing the flame and accelerant onto Satish when he called her a "fat bitch".
Jurors accepted her version of events, acquitting her of murder and finding her guilty of the lesser charge of manslaughter.
In sentencing, Justice Sulan said Narayan had "deified" her husband and was "shattered" by his betrayal.
He said there was "no doubt" her thinking at the time was "unrealistic, muddled and illogical".
"For the first time in your life you had confronted your husband, had found the courage to be assertive to the person who had mistreated you for 20 years," he said.
"His response was to treat you with disdain, dismiss you and turn his back to you (and) you snapped." Justice Sulan further ordered Narayan be under Correctional Services supervision for two years, and undertake psychological counselling as ordered.