If he gives his son a car, does he have to give the same to his daughter too?
Question

                I have two sisters, one of whom is married and the other is still in school. When my sister got married, my father helped her by selling another apartment that he owned. A few years later, Allaah made things easier for us. Now I am at the age to get married, and my father has started to give me things I need to get married. A car has become one of the essentials in my case, and my father gave me his car. Is this fair? If the answer is no, should my father give my married sister a sum of money?.
Praise be to Allah.
    Firstly: 

    It is obligatory to treat children fairly in giving gifts, 
    and it is haraam to show preference to some over others, unless that is for 
    a legitimate reason, such as need, as is explained in the answer to question 
    no. 22169. 

    A gift is something that a father gives as a present to his 
    children. As for maintenance, that depends on the child’s needs, and it is 
    not essential to give each one the same. Whoever is in need of maintenance 
    may take it, and whoever does not need it should not take it. It is well 
    known that maintenance of a minor is not like maintenance of a grown-up, and 
    the maintenance of one who is studying at the primary level is not like 
    maintenance of one who is studying at university, and maintenance of a girl 
    is not usually like maintenance of a boy. That includes maintenance with 
    regard to marriage – a father may give to one who is about to get married 
    what he does not give to one who is not about to get married. 

    Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said: If 
    we assume that one of them is in school and needs support with regard to his 
    schooling, such as books, exercise books, pens, pencils and the like, and 
    the other one does not read, and he is older than him but he is not in need, 
    if he gives to the former must he also give to the latter? 

    The answer is that he does not have to, because fairness in 
    maintenance means giving each one what he needs.  

    For example: if a male child needs a ghutrah (head cover) and 
    skullcap that cost one hundred riyals, and a female needs earrings that cost 
    one thousand riyals, what is fair? 

    The answer is: What is fair is to buy the headgear worth one 
    hundred riyals for the boy and to buy earrings for the girl that are worth 
    ten times more than what he bought for the boy; this is proper. 

    Another example: if one of them needs to get married and the 
    other does not need that, what is fair? 

    The answer is that he should give to the one who needs to get 
    married and not to the other. Hence it is regarded as a mistake to do what 
    some people do, when they have married off those of their children who have 
    reached marriageable age, and they have younger children, so they write in 
    their will, “My children who are not yet married are to be married off using 
    one-third of my estate.” This is not permissible, because marriage comes 
    under the heading of meeting needs and these children have not yet reached 
    marriageable age, so bequeathing this wealth to them is haraam and the 
    bequest should not be carried out. Even for the heirs, it is not permissible 
    to carry out this bequest except for those who have reached puberty and are 
    of sound mind. If that is allowed there is nothing wrong with it with regard 
    to his share of the estate. End quote from al-Sharh al-Mumti’ 
    (4/599). 

    Based on that, if the car is something that you clearly need, 
    and you cannot afford to buy one, then this comes under the heading of 
    maintenance, and your father does not have to give your sister something 
    similar or of similar value. If you do not have any real need for it, or you 
    have enough money to buy a car yourself, then what your father has given you 
    comes under the heading of a gift, and in that case he has to treat all his 
    children fairly, and give the daughter half of what he gave to his son, 
    because fairness between them means giving them in the same manner as the 
    inheritance is divided, according to the more correct of the two scholarly 
    opinions.

    And Allaah knows best.