How nice that the school is obviously in such close proximity to their home, since Maxima apparently still had her morning robe on. That long beige wolly thing was a bath or morning robe, now wasn't it? Her hair also looked like she just got up, had a coffee and then dropped the little one off at the busstop.
I bet donuts for dollars that it wasn't her first day at a new school.
If I was in Maximas shoes, I had asked for the teacher to come home to Amalia to get to know her and to let the child get to know her. I am sure that such a thing would indeed be possible for the future Queen. Plus I could imagine, that the staff had to be briefed as to security etc too.
I would also bet that Amalia already had a couple of "visits" at the school. This is something normal here in Germany, the children come in for some hours on several days, get to know the house, the teachers and possibly the other kids.