After deliberating parts of two days, jurors found Julie Harper, 42, guilty of murder and the use of a gun.
It was the second trial for the defendant, who faces up to 40 years to life in prison.
Another jury last year acquitted her of first-degree murder and deadlocked on second-degree murder.
Deputy District Attorney Keith Watanabe told the jury in the retrial that the mother of three shot her husband from behind as they argued in their upstairs bedroom on Aug. 7, 2012.
Watanabe said the defendant disposed of the murder weapon, which has never been found, and did not call 911. The prosecutor called the shooting "unjustified.''
Watanabe acknowledged that Jason Harper was verbally abusive toward his wife but said the victim was never physically violent with the defendant.
Harper testified that she shot her spouse of 10 years in self-defense because she feared he was going to kill or rape her. The couple's children were in a downstairs room watching cartoons at the time.