Is it permissible for Reem to marry the brother of the deceased person whose mother breastfed her own mother?

The questioner is not permitted to marry the suitor if he is her maternal uncle through suckling, meaning that one of them suckled from the other's mother, or they both suckled from the same woman. However, merely sharing a suckling mother between her mother and her suitor's brother does not prohibit the marriage. The suckling that prohibits marriage consists of five satisfying sucklings.