He—may Allah have mercy on him—was also asked:

A judge annulled a woman’s marriage shortly after she gave birth, having established that she had suffered harm because her husband had ceased providing maintenance and had failed to act toward her as prescribed by Islamic law, for a period sufficient to warrant annulment in her circumstances. Three months after the annulment, someone wished to marry her. May she calculate her waiting period in months, since most women do not menstruate while breastfeeding, or must her hardship continue until breastfeeding ends and her menstruation returns?

He replied:

Praise be to Allah. Rather, she must remain in her waiting period until she has had three menstrual periods, even if this is delayed until the breastfeeding period ends. This is agreed upon by the four imams and others. ‘Uthmān ibn ‘Affān and ‘Alī ibn Abī Tālib ruled accordingly among the Emigrants and the Helpers, and no one disagreed with them.

If the woman wishes to engage a wet nurse for her son so that her menstruation may return, or to drink something that will induce menstruation, she may do so. And Allah knows best.

He—may Allah Most High have mercy on him—was also asked:

A woman used to menstruate while she was still a virgin. After marrying, she bore six children and did not menstruate thereafter. She separated from her husband while she was breastfeeding and stayed with her family