Everyone has the same mistake. A lot of people did lvl up in a year. Not only Aiz. For example, Ryu came to the family at 11, and at 14, during the battle with Alfia, she already received 4 lvl. Allen seems to be doing lvl up even faster. It's just that Loki is the only one running around demanding to document Ais's greatness. ) The fact is that the author refutes with all the facts that Aiz is very talented. Also in comparison, with Alfiya, Aiz, Ryu, Allen are very ordinary. Alfiya was lvl 7 at the age of 16.