بسم الله الرحمن الرحيم
(Fatwa: 1458/523/L=11/1434)
One may not make a will for his or her heir; therefore a will made for an heir will be invalid, it will be valid only when all the heirs allow the same. If you survived all these heirs after your death, then all the wealth and property left by you will be distributed in 96 shares after due rights preceding inheritance. Out of the total, 12 shares shall go to your wife, 16 to mother and 16-16 shares to each daughter, while each of your sisters will have 1-1 share.
This distribution will be cancelled if any of your heirs died before you.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband