All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
If the deceased did not leave any other heirs except those mentioned in the question, then his wife gets one-eighth as her legal share due to the existence of the children (direct heirs); Allaah says (what means): {But if you leave a child, then for them [i.e. the wives] is an eighth of what you leave, after any bequest you [may have] made or debt.} [Quran 4:12]
The daughters get two-thirds as their legal share, as Allaah says about the existence of a number of daughters (what means): {But if there are [only] daughters, two or more, for them is two-thirds of one’s estate.}[Quran 4:11]
The remainder after the share of the wife and daughters is deducted shall be returned to the daughters because there is no 'asabah (i.e. paternal relative entitled to inherit what remains after other heirs get their fixed shares) nor an organized Muslim treasury.
Therefore, the inheritance should be divided into 24 shares, the wife gets one-eighth, which is 3 shares, and each daughter gets 7 shares as both their allotted share along with what is returned to them after the division of allotted shares in proportion to their original shares).
With regard to the will of the deceased to give the entire inheritance to his wife during her lifetime, then this is a will for an heir, and it is not effective unless all the daughters agree to it provided that they are eligible to act and dispose of their properties by being mature adults with a sound mind. Please, refer to fatwa 312970.
Finally, it should be noted that the matter of inheritance is a very complex issue, so it should not be divided without taking the matter to an Islamic court, if available, in order to fulfill the interests of both the living and the dead.
Allaah knows best.