Giving the son the share of two daughters – is that only applicable to the shares of inheritance?
Question

Is the verse {for the male, what is equal to the share of two females} [An-Nisa’ 4:11], applicable only to the shares of inheritance, or does it apply to all other issues? For example, when a father gives pocket money to his children, should he give the boys ten and the girls five? Is that permissible, noting that the girls are older?
Praise be to Allah.Firstly:
Allah, may He be exalted, says (interpretation of the meaning):
{Allah instructs you concerning your children: for the male, what is equal to the share of two females} [An-Nisa’ 4:11].
This verse has to do with the division of the estate. In the event of the father’s death, what he leaves behind is to be divided amongst his children in this manner.
Secondly:
With regard to what a father gives to his children when he is still alive, it is of two types:
The first type:
is what he gives them by way of maintenance, which the father is obliged to provide for his children. This is to be done according to need. A daughter may need more than a son, or vice versa, according to the need of each of them.
It says in al-Mawsu‘ah al-Fiqhiyyah al-Kuwaitiyyah (41/81):
The jurists are unanimously agreed that what is required with regard to the maintenance of relatives is what is sufficient of bread, condiments, clothing, shelter and breastfeeding, for an infant, because there is a need for these things, and they are to be estimated according to what meets the need. End quote.
Based on that, if the children’s needs are equal, then the father must give equally to males and females. If their needs are different, then he must give each of them as much as will meet their needs.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
There is another type of need which applies equally to all the children, namely the case of gifts, maintenance or arranging marriages. Undoubtedly, in that case, it is haram to differentiate between them."(Al-Fatawa al-Kubra  5/435).
One example of that is what a father gives to his children – as mentioned in the question – of pocket money. This comes under the heading of maintenance, so the share of the male does not have to be the share of two females; rather the father should look at what each of his children needs, and give him what will suffice him, taking into account the child’s age and gender, because in this regard, one who is younger is not like one who is older, and one who is male is not like one who is female. The father should strive to be equitable in that regard. He may think that being equitable means giving each child, male or female, the same, if they are close in age.
The second type:
is what the father gives to his children by way of showing kindness, without it being based on the need that calls for that. This refers to gift giving, in which Islam teaches parents to treat their children equitably. So it is not permissible to give to one child and not to another, because of the hadith of an-Nu‘man ibn Bashir (may Allah be pleased with him), who said: My father gave me a gift, but [my mother] ‘Amrah bint Rawahah said: I will not approve until you ask the Messenger of Allah (blessings and peace of Allah be upon him) to bear witness. So my father went to the Prophet (blessings and peace of Allah be upon him) and said: I have given a gift to my son from ‘Amrah bint Rawahah, but she told me to ask you to bear witness, O Messenger of Allah. He said: “Have you given a similar gift to all your children?”
He said: No.
He said: “Fear Allah and treat your children fairly.” So he came back and took back his gift.
Narrated by al-Bukhari (2587) and Muslim (1623).
According to a report narrated by Abu Dawud (3544) from an-Nu‘man ibn Bashir, he said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Treat your children fairly, treat your children fairly.”
The scholars differed as to how the father should treat his children fairly in this case. Does fairness mean giving the same to males and females, or does it mean giving according to the division of the shares of inheritance, with the male receiving the share of two females?
Muhammad ibn al-Hasan, the companion of Abu Hanifah, and a number of the Malikis, Shafa‘is and Hanbalis – according to their famous view – were of the view that fairness means giving in accordance with the shares of inheritance, with the male receiving the share of two females.
Al-Hafiz Ibn Hajar (may Allah have mercy on him) said:
Then they differed as to what is meant by giving equally. Muhammad ibn al-Hasan, Ahmad, Ishaq and some of the Shafa‘is and Malikis said: Fairness means giving the male two shares, like the shares of inheritance. They quoted as evidence the fact that this is what the female’s share of that wealth would be if the giver left it behind when he died."(Fath al-Bari  5/214).
Some scholars are of the view that fairness means giving equal shares. Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said:
Children should be given according to what Allah, may He be glorified and exalted, said in His Book about inheritance: {for the male, what is equal to the share of two females} [An-Nisa’ 4:11]. Undoubtedly nothing is more fair than the way in which Allah, may He be glorified and exalted, divided the shares of inheritance. Whoever says that there is a difference between when the parent is alive and when he is dead must provide evidence for that. Hence we say: in life and after death, it is the same."(Ash-Sharh al-Mumti‘  11/80).
And Allah knows best.