Is the woman mentioned in the question considered revocably divorced (ṭalāq rajʿī) or irrevocably divorced (bā’in), necessitating a new marriage contract? And does her despair of conceiving affect her being considered despairing of menstruation (yā’is min al-ḥayḍ), knowing that her age is 46? And is it permissible for her brother to marry her off without the knowledge of her absent son?

A divorced woman who is menstruating observes an 'iddah (waiting period) of three menstrual cycles, and a woman who has reached menopause observes an 'iddah of three months. If a woman's menstruation becomes irregular due to a known reason, she waits for it to return or until she reaches menopause (in which case she observes an 'iddah of three months). If the reason is unknown, her 'iddah is a full year.

The woman mentioned is still in her 'iddah and cannot marry before its completion.

Regarding the guardianship for a woman's marriage (wilayat tazwij), scholars differ. The Hanafis and Malikis prioritize the son, then the father. The Shafi'is do not grant guardianship to the son; they prioritize the father, then the grandfathers, then the brother.

It is advisable to refer the matter to the Sharia court for a ruling.