Jazakallah Khaeran Sheik, even Seyidah Aishat was between 19 to 21 years when the holy prophet SAW married her. Not 14 to 18 years sir Seyidah Aishat was 17 years when Prophet SAW migrated to Madina and it was after 2 years of migration that the holy prophet shows interest on her while she was married after another 2 years Therefore 17 +2 +2 = 21 years Asalam alaykum waramatullahi