{ And those of your women who despair of menstruation, if you have doubts, the time of watchfulness is three months, and those who have not yet menstruated } Al-talaq 4

And accordingly for little ones who have not yet reached the age of menstruation, that their waiting period ['iddah] is like the waiting period for post-menopausal women – three months; this is why the Most High says { And those who have not yet menstruated } .