The property rights under Islam differ based on a person’s status of life or death. During the lifetime of a brother or sister, the owned property respectively have their own rights to property owned by them. In other words, the brother’s property earned by his own effort will be considered his own during his lifetime. Similarly, the sister’s property earned by her own effort will be regarded as her own during her lifetime.

But, after the death of either brother or sister, the property becomes an estate governed under mirath (i.e., Islamic Inheritance Law). You can learn more about Muslim siblings’ inheritance here and calculate here.

The lifetime gift is restricted to one-third as per this Hadith narrated Sa'd bin Abi Waqqas (RA): I said, "O Allah's Messenger, I have wealth and no one to inherit from me except my one daughter. Shall I give two-thirds of my property as Sadaqah?" He replied, "No." I said, "Shall I give half of it as Sadaqah?" He replied, "No." I said, "Shall I give a third of it as Sadaqah?" He replied, "You may give a third as Sadaqah, which is still a lot. To leave your heirs rich is better than to leave them poor and begging from people." - Book 7, Hadith 959

in many scenarios, this Islamic ruling is compromised and some of the examples are as below.

1. Brother owned the property from his own efforts. Other siblings demand a share of the property.

2. Sister owned property and other siblings demanded a share of her property.

3. Father gave Brother a gift from his property and deprived other siblings of getting gifts without any valid Shariah reason.