بسم الله الرحمن الرحيم
In the above mentioned case, the whole property left by your father shall be divided into 72 shares. Out of the total, 9 shares shall go to your mother, 6 shares to your phuphi from your grandmother and you shall receive 38 shares while your sister 19 shares.
The detail of division is as follows:
Note: This division is correct provided your grandmother left only you, your sister and your phuphi as her legal heirs.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.