Madam Aishah, a Study of her age at the time of her marriage with Prophet Muhammad

Historical Fact 3. Abu Bakr’s marriage to Umm Ruman:

Abu Bakr married Umm Ruman when he was 28. So, if we make the natural assumption that their children Abdur Rahman and Aishah were born in the first 4-5 years of their marriage (assuming that she did not use birth control and breastfed her children), then it would mean that Abu Bakr would most likely have been around 32-33 years old when Aishah was born. The Prophet is known to have been two years older than Abu Bakr, so at this time, he would have been 34-35.

Now, since we know that the Prophethood was bestowed upon him in his 40th year, it once again adds up to the conclusion that Aishah must have been born 5-6 years prior to the Prophethood, i.e. in c 605 CE, and that would make her 19 and not 9 a the time of her marriage.