Studying is what Ami is famous for. She is the group nerd, usually to be found with her nose in a book memorizing things while the others talk around her. She's the one who keeps them on track, and makes sure they knuckle down and revise for their high school entrance exams, at least in the anime, and tries her hardest to become a doctor like her mother, in every incarnation of the series.
In the anime at one point Umino remarks her I.Q. is 300, but this is probably just a rumor that's going around, as I.Q's don't go quite that high. She is very intelligent, however, and sometimes has to be reminded that studying is not the be all and end all of existence. She will loosen up and agree to go to the park or do other things aside from study, such as swim, but it is clearly something that is very important on her agenda of things to be done.
In PGSM things are no different, Ami attends cram school, and spends most of her breaks at school up on the roof studying by herself and eating sandwiches. She enjoys the knitting they're taught in domestic science so much that she spends free time at CROWN knitting mittens for the other senshi and a scarf for Luna.
Ami is one of the few senshi who seems familiar with computers for something other than playing games on. She knows how to navigate her way around the web, and can even find and read Harvard's website. She will even read at times when they're supposed to be relaxing, such as during a couple of the vacation episodes in the anime.