What is the ruling on the fasting of a woman who has reached menopause if menstrual blood flows?
If a woman reaches the age of menopause (which is usually sixty-two) and her menses have ceased, then she sees blood after that, and its duration is not less than a day and a night (24 hours), it is menstruation (hayd). If it is less than a day and a night, she is considered as having non-menstrual vaginal bleeding (mustahada), so she fasts and prays. However, she must perform ablution for every obligatory prayer after its time enters, pray immediately, and be treated as a person with a continuous condition. There is no specific end limit for a woman's menstruation; it is possible as long as the woman is alive. And Allah the Almighty knows best.
How is the Night Prayer (Qiyam al-Layl) performed?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Night Prayer (Qiyam al-Layl) refers to the voluntary (Nafl) prayers performed by a person after the Sunset prayer (Maghrib) and before the Dawn prayer (Fajr). As for Tahajjud, it is the voluntary prayer performed during the night specifically after waking up from sleep, as an act of devotion to Allah. Allah the Exalted says {what means}: "And from [part of] the night, pray with it [i.e., recitation] as additional worship for you." (Al-Isra/79). Thus, in terms of reward,Tahajjud is superior to voluntary prayers performed before sleeping. And Allah the Exalted knows best.
What is the ruling on public street water if it gets on a person's clothes or body?
The default ruling is that public street water is pure (tahir). If one is certain of its impurity (najasa), then a small amount that gets on the lower part of a person's clothes or body is overlooked (excused). And Allah the Almighty knows best.
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.