If a woman becomes pure from menstruation shortly after Fajr in Ramadan, what is required of her?
If a woman becomes pure (from menstrual period) after Fajr, even shortly after, it is recommended (but not obligatory) for her to refrain from eating and drinking for the rest of the day. However, she must make up for that day after Ramadan.
She will be rewarded for both refraining from eating (imsak) and making up the fast (qada) since she was menstruating for part of the day.
My father has debts and asked me to repay them years ago, and I promised him I would do so upon his death — is it permissible for me to go back on my promise given that I am unable to repay them, especially since he refuses to contribute to repayment on the grounds that the debt has become my responsibility by virtue of my promise?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
The established principle is that a father's debt is to be repaid from his own wealth, if he possesses sufficient means. As for the promise made by the son to repay it on his father's behalf, fulfilling such a promise is strongly recommended, and breaking it is considerably disliked. Shaykh al-Islām Imām al-Nawawī, may Allah have mercy upon him, states: "Fulfilling a promise is emphatically recommended, and breaking it is severely disliked. The evidences for this from the Qurʾān and the Sunnah are well known." [Rawḍat al-Ṭālibīn,Vol. 2/P.278] Shaykh al-Islām Imām Zakariyyā al-Anṣārī, may Allah have mercy upon him, further states: "The reason fulfilling a promise is not obligatory and breaking it is not forbidden is that a promise is in the nature of a gift, and a gift does not become binding except upon receipt." [Asnā al-Maṭālib fī Sharḥ Rawḍ al-Ṭālib,Vol. 2/P.487]
Given that the son does not possess the financial means to fulfil his promise to his father, breaking this promise falls beyond his capacity — and Allah does not burden a soul beyond what it can bear. Since the father himself possesses sufficient wealth to settle his own debt, repayment must be made from his own funds. Should he pass away before doing so, the debt is to be settled from his estate. And Allah the Almighty knows best.
What is the ruling on undoing braids of hair during the ritual bath?
It is not a condition to undo braids if the water reaches all the hair and penetrates to its base. If the water does not reach except by undoing the braids, then it is obligatory to undo them for the water to reach. And Allah the Almighty knows best.
What is the ruling on one who performs ablution or the ritual bath while having nail polish?
Nail polish must be removed before ablution or ritual bath so that water reaches what is beneath it, because it is a barrier that prevents water from reaching that area. This is based on the hadith narrated by Ali (may Allah be pleased with him) from the Prophet (peace be upon him): "Whoever leaves a hair's breadth of his body unwashed from major impurity, such and such will be done to him in the Fire." (Reported by al-Bukhari). And Allah the Almighty knows best.