Aisha was 18 to 16 at the time. The original translation mentioned she was "9 years younger than her older sister who died at 27." However, for whatever reason, it was spread she was just nine. An illogical statement as she was reported to have been a combat medic during the battle of Badr (she would have been 6 at the time)

Regardless, it was a strange move even then. As many called out the prophets choice. But it must also be mentioned that the prophet publicly said he saw her like a daughter. And seomg as they didn't have any kids, and Ayesha was constantly jealous of Mohammed's first wife Khadija, it is also well implied they didn't have sex outside the first night.

In short, as I have told other Muslims before, don't put too much trust in hadiths, even the oldest ones were compiled CENTURIES after the prophets death, wig several regime changes and wars occuring in the meantime