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 heirs except those mentioned in the question, then the two wives get together one-eighth of the inheritance as their legal share. 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 remainder will be divided amongst the son and the two daughters by Ta’seeb (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 twice the share of the female as Allaah 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 inheritance should be divided into 32 shares, the two wives get [together] one-eighth, which is 4 shares which means 2 shares for each of them, the son gets 14 shares and each daughter gets 7 shares.
Allaah Knows best.