Does the phrase "entered upon her" signify the act of marital relations that results in procreation, and if so, why did Lady Aisha (may Allah be pleased with her) not bear children, and what is the wisdom behind that?

"Entering upon one's family" is a term referring to the private seclusion in which one enjoys and has intercourse with his wife. It is a euphemism for sexual intercourse, as stated in the Almighty's saying: "from among your women whom you have entered upon." As for Aisha not having children, there is no issue with that, for procreation is solely in the hands of Allah, and He, glory be to Him, says: "To Allah belongs the dominion of the heavens and the earth; He creates what He wills. He gives to whom He wills female [offspring], and He gives to whom He wills male [offspring]; or He makes them [both] males and females, and He renders whom He wills barren. Indeed, He is Knowing and Competent."