1,829. Who Must Wait 90 Days to Marry?
Hilchos Geirushin 11:19
We count 90 days from the day a get is written. This is so even if the get was written conditionally or was not delivered to the woman for years. The reason for this is because once a get has been written, a man can no longer be secluded with his wife.
Hilchos Geirushin 11:20
The rabbinic enactment of waiting 90 days applies even to a woman who can’t have children, and even to women who were divorced or widowed after betrothal. Accordingly, the 90-day rule applies to a minor, a post-menopausal woman, an infertile woman, a woman who never matures physically, a woman whose husband is overseas, sick or in prison, and even to a betrothed woman who is still a virgin.