Ah, they were a primative people, who developed algebra, astronomy, fine cuisine (well some of it), medicine, and written language...
Anyway. As usual it will boil down to cultural practice. My relatives in one part of the ME obviously live with sharia law. You can still leave your money to whoever you want, but traditionally it will be a bigger cut to your sons. Usually, however, the daughters do get a cut but also are given money/property by their mums (not usually the sons, now) who, as they have had the right to hold in their own right, control their own property. And remember, daddies do help out their daughters in their lifetimes too and buying homes is not unheard of before a marriage to guarantee a home if a marriage breaks up (which is pretty cool in my eyes as the ex can't get his hands on it).
Now, this 'civilized' behaviour may not happen with the muslim equivalent of the Jeremy Kyle types (oh yes, there are shits in all religions and none) but this is what I see happening. I have also known hugely massive estates all going to charity.
I am sure the ratbags will use it to their benefit. As long as it doesn't extend to parental 'rights' after divorce. Hats a sticky one.