Is it permissible for the questioner's sister to marry her paternal cousin, given that the questioner's mother breastfed a younger brother of her paternal cousin a full suckling, and the questioner herself was breastfed by her paternal cousin's mother?

"Suckling prohibits what lineage prohibits. So, a child who suckles from a woman becomes a son to her and to her husband, the owner of the milk. This prohibition applies only to the suckling child himself, not to his brothers and sisters. If no valid legal suckling is established between your cousin and your sister, he is permitted to marry her. Your suckling from your cousin's mother, and his brother's suckling from your mother, does not prohibit your sister from marrying her cousin. It is a condition for suckling to be prohibitory that it consists of five sucklings."