What is the waiting period for a divorced woman if she is breastfeeding and not menstruating, knowing that the absence of menstruation does not prevent pregnancy during this period?

A woman must remain in her iddah until she experiences three menstrual periods, even if this extends beyond the nursing period. This is by agreement of the four Imams and others. It is permissible for a woman to nurse her son (from another woman's milk) in order to induce menstruation, or to drink something that stimulates menstruation.