• How is night prayer offered ?
Night prayer is offering voluntary prayer after Maghrib and before Fajr(dawn). As for Tahajjud, it is offering voluntary prayer at night after waking up voluntarily, and for Allah`s sake as He says: “And pray in the small watches of the morning: (it would be) an additional prayer (or spiritual profit) for thee: soon will thy Lord raise thee to a Station of Praise and Glory!”{Al-Isra`/ 79}. Offering Tahajjud is better than offering voluntary prayer before going to bed.
• Is it permissible for the mother to give her children from the Zakah(obligatory charity) of her money?
It is permissible for the mother to give her children from the Zakah of her money if they are Zakah-eligible recipients, and she isn`t obliged to provide for them.
• Should the Zakah(obligatory charity) giver tell the poor recipient that this is the Zakah of his money?
No, he shouldn`t. But, the Zakah giver should make an intention in his heart that it is the Zakah of his money when he gives it to the poor.
• One day, I swore that my wife will be unlawful to me to quit smoking hookah?
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
The best course of action is that you turn to Allah for help and quit the hookah. In addition, acquainting yourself with the risks of smoking hookah will help you take this step.