It is permissible for a husband to give his wife whatever he wants of his wealth, and he does not have to be fair between her and his children, but that is subject to the condition that he does not aim to harm his heirs by doing that.
Allaah has enjoined upon fathers and mothers to be fair towards their children in giving gifts. It is not permissible for them to give to one and not the others. If they do that, they must either take back what they gave, or give the rest something as well so as to be fair.
What your mother has done by giving an apartment, a store and another place to your brother is something that is haraam. What she must do is to treat you both fairly.
It was narrated from al-Nu’maan ibn Basheer (may Allaah be pleased with him) that his father brought him to the Messenger of Allaah (peace and blessings of Allaah be upon him) and said, “I have given this son of mine a slave.” He said, “Have you given a similar gift to all of your sons?” He said, “No.” He said, “Then take it back.” Narrated by al-Bukhaari, 2446; Muslim, 1623. According to another version narrated by al-Bukhaari (2587): “Fear Allaah and treat your children fairly.” He said: So he went back and took back his gift.
In the answer to question no. 67652 we have stated that it is obligatory for a mother to treat her children fairly in gift giving, and that fairness in gift giving means that the male gets the share of two females, because there is nothing more just than the shares allocated by Allaah.
And Allaah knows best.