Must a woman who strangled her infant to death after conceiving and giving birth to it throughZina (fornication/adultery) inform her husband of that?

The wife is not obligated to inform her husband about killing her child or committing adultery. Rather, she must conceal her sin, based on the Prophet’s (peace be upon him) saying: “All of my Ummah are forgiven except for those who publicize their sins…” She must strive to protect herself, safeguard her honor, and avoid every means that could lead her to fall into indecency again.