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.
The second wife and her two daughters have no share in the inheritance of the first wife as there is no reason of inheritance between them and her.
So, if the deceased did not leave any other heirs except those mentioned in the question, then her husband gets one-fourth of the inheritance as his legal share due to the existence of the children of the deceased as Allaah Says (what means): {But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt..}[Quran 4:12]
The remainder should be divided amongst the sons and the 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 8 shares, the husband gets one-fourth, which is 2 shares, each son gets 2 shares and each daughter gets 1 share.
Allaah Knows best.