Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.
Is it incumbent on the fiancée to obey her fiancé?
When the woman settles in her husband`s house, it is incumbent on him to provide for her and it is incumbent on her to obey him. Before that, and if the marriage contract had been concluded, then she is lawfully his wife and thus she should abide by custom in treating him, but if the marriage contract hadn`t been concluded, then she should treat him as a non-Mahram (Marriageable).
What is the ruling on a woman who learns of her divorce or her husband's death after her *ʿiddah* has ended? And does the *ʿiddah* of a woman who abandoned mourning (*iḥdād*) for the whole period of the *ʿiddah*, or part of it, still end, even though she knew that abandoning it is forbidden?**
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
The waiting period of a widow who is not pregnant is four months and ten days, based on the saying of Allah Almighty (which means): “And those of you who die and leave wives behind, they shall wait concerning themselves for four months and ten days” [al-Baqarah/234]. If she is pregnant, her ʿiddah ends with the delivery of her child. The ʿiddah is calculated by lunar months and begins from the date of death.
If her ʿiddah ends before she learns of her husband’s death, or of his divorcing her, she does not observe the ʿiddah upon learning of it, because her ʿiddah has already ended.
It is stated in al-Bayān fī Madhhab al-Imām al-Shāfiʿī (Vol.11/p.41), one of the books of the Shāfiʿī school: “If a man divorces his wife, or dies while he is absent from her, her ʿiddah is from the time of the divorce or from the time of death. If she does not know of the divorce or the death until her ʿiddah period has ended, then her ʿiddah has ended. If she learns of it before the end of the ʿiddah period, she completes her ʿiddah counting from the time of the divorce or death.”
As for a woman who abandoned mourning throughout the ʿiddah while knowing that it is forbidden, she is sinful, although her ʿiddah has nonetheless ended. And Allah Almighty knows best.
What is the ruling on wiping the front of the head beneath the ḥijāb, and is it permissible to wipe over the ḥijāb if it was put on while in a state of purification (wudu`)?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
It is permissible to wipe the front portion of the head (nāṣiyah) with the fingertips. It is likewise sufficient to place a wet hand over a head covering (ḥijāb), provided the moisture actually reaches the hair beneath it — if it does not, it does not suffice. A head covering is not treated in the same manner as leather socks (khuff) and may not be wiped over in lieu of the head itself.
Imām al-Nawawī, may Allah have mercy upon him, states in al-Majmūʿ (Vol.1/P.407): "If a person is wearing a turban and does not wish to remove it — whether for a valid reason or otherwise — he should wipe the entire front portion of the head... The same ruling applies to whatever a woman wears on her head. If, however, he confines himself to wiping over the turban without wiping any part of the head itself, this does not suffice — and there is no disagreement among us on this point." He further states: "A woman is like a man in the manner of wiping the head... She should insert her hand beneath her head covering so that the wiping falls upon the hair itself. If she places her wet hand over her head covering, our scholars stated: if the moisture does not reach the hair, it does not suffice her." And Allah the Almighty knows best.