Jesus never raised the issue of her guilt. Adultery was a serious crime, and due to social needs for strong families and proper inheritance, was considered a grave crime punishable by death. Was the adulterous woman “reformed”? Before Jesus’ final admonishment to her, we have no evidence of that. Was it possible, or even likely she might sin again unless stopped? Sure. We can consider society was at risk for her future misdeeds.
So while the adulterous woman met many of the criteria for a “just” execution, Jesus intervened and stopped it when He was asked about the matter.
Why is the story only about the woman taken in adultery? What happened to the man she was committing adultery with? Had he already been killed, or had he managed to escape?