The third question of Fatwa no.
if a person's brother has a daughter who is a grandmother, is it permissible for her paternal uncle to marry her granddaughter?
It is not permissible for him to marry her. This is according to the general consensus of Muslim scholars; because he is her grandmother's uncle, and a grandmother's uncle is considered her uncle, and her descendants' uncle. (Part No. 18; Page No. 199) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.