Adultery அவள் இதயத்தின் மொழி

[Shajith]

Let the author say she is woman with high libido and continue instead projecting her as pure, loving and doting wife.

That's your interpretation, and you're entitled to it. But a character can be emotionally conflicted. Human emotions are rarely black and white. A person may struggle between duty, affection, desire, guilt, and responsibility at the same time. Exploring those contradictions is part of storytelling. If you think the characterization isn't convincing, explain which scenes led you to that conclusion. That would be a meaningful literary discussion.