Is it permissible for a mother to give one of her children her car, valued at one and a half million Syrian liras, without the others, and would she be considered sinful for that, even if the siblings agreed and were well-off?

Justice among children in giving gifts is an obligation upon the mother as it is upon the father, because singling out some of them for gifts engenders envy and animosity. However, if all the children consent to this preferential treatment, there is no objection to it, as Abu Bakr did with Aisha and Omar with Asim.