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, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
If the deceased did not leave behind any other heirs except those mentioned in the question, then his wife gets one eighth of the estate as a fixed share because the deceased left children; Allaah, The Exalted, says (what means): {...But if you leave a child, then for them is an eighth of what you leave...} [Quran 4:12]
The remainder of the estate should be divided among the deceased's children by virtue of Taʻseeb (by virtue of having a paternal relation with the deceased and not having an allotted share, so they get what is left after the allotted shares have been distributed); the male gets twice the share of the female.
Hence, the estate should be divided into sixteen shares; the wife gets one-eighth (two shares), each son gets two shares, and each daughter gets one share.
As for the father's will regarding giving lesser shares to the two daughters because they are married, it is an invalid will, and it is impermissible to execute it because it contradicts the sharee'ah. Allaah, The Exalted, says (what means): {Allaah instructs you concerning your children (i.e. their portions of inheritance): for the male, what is equal to the share of two females.} [Quran 4:11]
Therefore, the deceased was not correct in making this will.
Allaah knows best.