If you see the Islamic literature this a big debatable issue and Islamic scholars differ over it and no one knows what excatly was the age of Prophet Muhammad's (PBUH)wife Aiyesha, no authentic source is there neighter it is mentioned in the Holy book Quran.

This Hadith cannot be correlated with any Aiyat of Quran Karim and at the same time all authenic Hadiths are corelated with the Holy Quran in some way and that is why they are called authentic. That is why the scholars say the doubt is there and the age cannot be ascertained.