Absolutely love the video!!! And the fact that her little dolls are black girls, that's so nice of you because she's going to be open minded about races etc.
In a real Montessori classroom they have way more than just 8 items on a self. We actually don’t use cube shelves in the Montessori classroom I worked in and we also had materials on the top shelf like you did. We also don’t follow the guide you showed with having one cube be for math, science, language ect. We have 1 shelf just for math, one shelf for language ect.