Do the sons and daughters of a deceased brother inherit from their paternal aunt who died before their father and who has one daughter?

The daughters of a brother do not inherit from their paternal aunt because they are not among the inheritors in the first place. As for the sons of a brother, if the son of a brother is from the mother's side, he does not inherit. However, a full-brother's son or a half-brother's son (from the father's side) inherits under certain conditions, including: the absence of a male descendant inheritor for the deceased, or a male ascendant inheritor, or a full-brother or a half-brother (from the father's side). The half-brother's son (from the father's side) inherits under the same previous conditions, in addition to the absence of a full-brother's son for the deceased.