Muslim law

Dear Sir,

In a Sunni Mohameddan family, A lady daughter of land lord died, with an Inherited estate to her name from her father.

Quaetion:  Mother is survived by only 2 daughters with no son. Since 2 daughters are entiled for only 2/3 rd share,

a )what will happen to remaining 1/3rd share of property ? If there are no residuaries to distribute  ?

b) what will happen to the 1/3 rd remaining share if there are residuaries ?

Thanks and Regards

Ali