Try to find me... hint: I was a good student. The school was started by German Benedictines in Rio.
Sunday update with a further hint (since this task sees to be dumbfounding all readers): Good students received medals each month. Mother Superior would come in the class, we would all rise, and a special tablecloth would cover the teacher's desk. She would give each girl her grades in alphabetical order, and only the perfect-grade students would receive a medal, which we were supposed to wear daily as part of the uniform. (We did tuck it in the collar when we were running). In this meantime I found the site of the German Motherhouse of the Benedictine Missionaries of Tutzing, where the sister originally came from. They seem to have schools in Africa, South Korea, the Philippines, and... Nebraska and MN as well.