Basic Rulings of the Waiting Period (`idda)
It is an obligation for a woman to undergo the waiting period (`idda) after being divorced (assuming the marriage was consummated) or after being widowed (regardless of consummation).
During this time, another man may not marry her nor make a proposal of marriage.
The divorced wife is entitled to financial support and housing from her husband during the waiting period, while there is no financial support owed to the widowed wife.
Length of the Waiting Period (`idda)
The length of the waiting period depends on the specific circumstances in question, based on the following:
(1) Three complete menstrual cycles: for a divorced woman who undergoes menstruation and is not pregnant;
(2) Three lunar months: for a divorced woman in menopause;
(3) Four lunar months and ten days: for a widowed woman that is not pregnant;
(4) Until she gives birth: for a pregnant woman, regardless of whether the marriage ended by death of the husband or divorce.
[Mawsili, Ikhtiyar; Maydani, Lubab]
Finally, it is advisable for the woman to consult a local scholar for more details and/or to deal with particular considerations.
And Allah knows best.
By: Shaykh Faraz Rabbani