My mother and father had a will that mirrored each others other

My mother and father had a will that mirrored each others other than their name change my mother died 4 years ago and father has just died in January. When mother died obviously everything became my dad's now however, on looking at the will can you explain the following clause
I bequeath the following specific legacies absolutely:
To my grandchildren all my shares stocks debentures debentious stock debts and other holdings of a capital nature of which I may be possessed or to which I may be entitled at the date of my death in equal shares.
Can "a capital nature" be translated as cash. The question is asked as my father sold the shares and put the money in the bank, so there are now no shares.
Further in the will it then says to pay all the rest and residue my children. If no shares and capital cannot be translated as cash does this now become part of "the rest and residue"
Reason for question is that we would like to pay the cash from the shares to grandchildren, but my sister who has no children may think that they are not entitled as should only have had shares.