We say: She has no right to remarry. Her maintenance does not lapse as long as she has not remarried. If she remarries, her maintenance lapses, because by marrying, she exits from his control and becomes a nashiz (disobedient/rebellious wife). If they are separated, she has no maintenance as long as she is in the 'Iddah period. Once it expires, if she does not return to her husband's dwelling, she has no maintenance either, because she remains in a state of nushuz (rebellion). If she returns to his dwelling, it is possible that the maintenance would resume, because the nushuz that caused the lapse of her maintenance has ceased, and it is possible that it would not resume because she did not surrender herself to him. If he returns and takes custody of her, her maintenance resumes. Whenever he provided for her, and then it became clear that the husband had died before that, what was spent on her from the time of his death is deducted from her inheritance. If she does not inherit anything, it remains as a debt against her, because she spent from the heir's wealth what she was not entitled to. As for her maintenance from the second husband: if we say she has the right to remarry, then her marriage is valid, and its ruling regarding maintenance is the same as any other valid marriage. If we say she does not have the right to remarry, then she has no maintenance, and if he provided for her, he does not recover anything, because he did so voluntarily, unless a judge compelled him to do so; in which case, it is possible that he could recover it, because the judge obligated him to perform what was not obligatory upon him, and it is possible he could not recover it, because what a judge has ruled cannot be overturned unless it contradicts the Book, the Sunnah, or consensus. If he separates from her through the judge's ruling or otherwise, she has no maintenance unless she is pregnant, in which case the obligation of maintenance is contingent upon the two narrations regarding maintenance: is it for the fetus, or is it for her because of it? If we say it is for the fetus, she is entitled to maintenance, because the lineage of the fetus is joined to him, so he is obligated to provide for his child. If we say it is for her because of it, she has no maintenance, because she is not in a valid marriage, thus it is analogous to the fetus of a woman engaged through an erroneous union (wat' shubha). If she gives birth to a child who could possibly be from the second husband, his lineage is joined to him, because she became his bed (a wife to him), and we have known that the child is not from the first, because she waited after his disappearance for more...
Al-Sunan al-Kubra 7/445; Sa‘id ibn Mansur, in: The chapter on the ruling regarding the wife of the missing person, from the Book of Divorce, al-Sunan 1/402; and Ibn Abi Shaybah, in: The chapter on what they said regarding a man who divorces his wife while she is experiencing istihada, regarding how she observes the waiting period, from the Book of Divorce, al-Musannaf 5/159. (81) In A: "maskanihā" (her dwelling). (82) In the original: "tūrath" (she is made to inherit). (83) In the original, B, and M: "fanambaghii" (it is appropriate). (84) In M, there is an addition: "min" (from).