What is the ruling of Islamic law concerning a woman who married and did not conceive a child with her husband until three years later, then consorted with another man without observing the iddah (waiting period) and became pregnant by him with a baby girl, and she does not know whether the child is her husband's or not, and is she obligated to inform her husband of this?

The woman must perform sincere repentance for the obscenity she committed. She must also seek forgiveness from her husband, unless she fears a greater harm, in which case she should generally seek his absolution without specifying the sin. She must be wary of illicit seclusion and mixing, and adhere to uprightness, the hijab, companionship with righteous women, and attending lessons of knowledge. The child is attributed to the woman's husband, as the Prophet, peace and blessings be upon him, said: "The child is for the bed." Her ignorance of whether her husband can procreate or not is not taken into consideration.