Hijab is a duty Allah Almighty prescribed for the Muslim woman, and she has to comply with that order and show her sincere faith in Allah, for He says: “And it becometh not a believing man or a believing woman, when Allah and His Messenger have decided an affair (for them), that they should (after that) claim any say in their affair.” (Al-Ahzab: 36)
Muslim parents should bring up their children according to the teachings of Islam. Parents have to make their children get used to doing the obligatory duties and avoiding haram (unlawful) things before puberty, so that it will not be too hard for them to adhere to Islamic rules after they reach puberty. The Prophet (peace and blessings be upon him) said: “Train your children to pray when they are seven years old, and smack them if they do not do so when they are ten, and separate them in their beds” (Reported by Abu Dawud).
From an early age, daughters should be taught that hijab is an ordinance from Allah to protect their chastity. When a girl reaches puberty she is obliged to do all the obligatory duties and to avoid all haram things. One of the obligatory duties is wearing hijab.
In this regard, Sheikh `Abdul-Majeed Subh, a prominent Azhar scholar, states:
“Fathers and mothers should note that they are responsible before Allah for the affairs of their daughters that have been entrusted to them; they should raise their daughters according to the Islamic manners. So if a girl is approaching puberty, there is the fear that her not wearing hijab may cause young men to be tempted by her or her by them. Hence in this situation her parent or guardian has to make her wear hijab so as to prevent means that may lead to evil or immorality.”
Given the above, it becomes clear that parents should encourage their daughters to wear hijab before the age of puberty so as to train them to wear it.