To be fair it's not like Kana and Pixie have had much of a formal education before you bring them to the college, and Ami seems verry eager to learn.
But you do have a point, I imagine Kana and Pixie having the educational level of a 10-12 years old, while Ami must be around 5 or 6 y/o learning to write and read.
Still It would be really cool if in the future, helping Ami with her education (even if it's not in the college) was an option, cuz she's such a precious little thing and I adore her. But the game is so f-ing good and Arc works so hard doing weekly updates that I would feel bad asking for more lol