How is the inheritance of a widow who has no children distributed, and her heirs are the children of her full brothers and sisters, and the children of her brothers and sisters from the father's side?

The sons and daughters of full sisters or paternal sisters are not among the inheritors, neither by فرض (fixed share) nor by تعصيب (residuary). As for the sons and daughters of full brothers or paternal brothers, only the males among them inherit by تعصيب (residuary). The sons of full brothers inherit exclusively and they preclude the sons of paternal brothers.