Question :
Is a woman`s nephew by suckling considered a Mahram ( i.e. unmarriageable) who is permitted to accompany her to Hajj?
The Answer :
All that is prohibited by lineage is prohibited by suckling, and a nephew by suckling is a Mahram like a nephew by lineage ;therefore, it is permissible for him to be a Mahram for his aunt in Hajj and Umrah. And Allah Knows Best.