Bismillahir Rahmanir Raheem
Wa'alaykum 'Assalam wa Rahmatullahi wa Barakatuhu,All Praise be to Allah who is the Lord of the Worlds, and may Endless Blessings be showered upon His Most Beloved and Final Messenger of Islam, Hadrat Muhammad Mustafa (Salla Allahu ta'ala 'alayhi wa 'aalihi wa Sallam)Jazak'Allah for your valued question. A brother is allowed to tell his sister to pray, as it is the duty of every Muslim, or it is a duty upon those people who have been qualified to give advice, to order what is right, and abstain people from doing that, which is wrong. The Qur'an al kareem says:
'Wa ta'muruna bil ma'rufi wa tanhawna 'anil munkar'
'You enjoin that, which is right, and forbid what is evil'.
(al-Imran, 3:110)
From this, we learn that it is the duty of every Muslim to be a preacher, and to propogate Islam. Whatever he knows, he must convey it to the others, verbally, and practically.
(Nur ul-Irfan, translation Kanz ul-Iman, Mufti Ahmad Yar Khan Na'imi (
Rehmatullahi ’Alaih).
An issue (
mas'alah) which is stated in the
'bahar-eshar'iyyat', states:
'When a child reaches the age of seven, he must be taught how to read salah, and when he reaches the age of ten, he can also be punished for not praying salah.' (Abu Daud, Tirmidhi).
The hadith quoted above states that a child who has reached the age of ten, should pray Salaah, regularly, upon his/her own accord, at the age of ten. This means that Salaah does become fard, and is very important from an early age. As regards to interpreting what we read, how and when we want to, then this is not allowed in Islam. There are a few conditions which must be fulfilled, prior to being able to interpret what the Qur'an al kareem and hadith say. For example:
*One must have command over the Arabic language, especially in lexographical, and epitomological (
sarf, nahw etc.) terminology.
*One must be acquainted fully, in the detailed, and the major aspects of shar'iyyah, also known as the
'fiqhi ahkam',especially when it comes to telling others about what a certain schools of thought says, or suggests.
He must practice what he preaches, for preaching anything that you do not practice yourself, is a form of hypocrisy. Furthermore, one must have the ability to derive meanings, and intended meanings from the Qur'an al kareem, and hadith, which do not contravene the principles of the beliefs of the mainstream
Ahl as-Sunnah wal Jama'ah. This duty is a duty that is placed upon the scholars
'ulama', who know what is to be interpreted in the light of what.
As regards '
istikhara', then this can be done as many times as one wishes, as there is no limit to how much good, a person can do, as praying the
istikhara salah, or using it's method, is a form of reward (
thawab), and anything that carries reward, has no limit to it, when it is being acted upon.
As long as X, and Y, are not breaking the rules of the
shar'iyyah, it does not matter when they perform their
istikhara. What they must not do is see each other, if they are
ghayr mahram, they definitely cannot have sexual relations, and cannot even be
'going out together', as they say.
In summary, there is no time limit as to when
istikhara can be said, whether it is before, or after ones liking, or fondness of another person.
In relation to your final question, then once a sister is married, then she has her own house. This means that she no longer has the same responsibility, which she used to have in her parents house, although she still has the right to serve her parents. The Qur'an al kareem says:
'wa bilwalidayni ihsana'
'those who did good to their parents'
This means that one should be good to his/her parents, regardless of if they are married or not. But in the case of a brother, then he has no right what so ever, to interfere with the personal life of his sister, especially if she is married. The woman has now her own issues, children, household to deal with, whom the brother has no part of, therefore he has no say. It is now the husband, who has the duty, and responsibility, of looking after the wife.
May Allah the Almighty protect all of us from the accursed shaytan, and may he keep us firm upon what is true, and help us fight that, which is evil. (Amin).Wallahu A'lamu BiththawaabM. Waseem Ashrafi