Sorry for the delayed response. I’ve consulted with a couple of people.
I don’t think there is one right answer. This being 1st grade material only complicates the problem. You have to be careful not to omit any of the buttons because it appears as though questions requires all of them. You could break it up and make a set of buttons with the shapes and letters on them for the colors. You could include a key for the color letters but would need to tell them in a TN before the key to ask their teacher for help. If you provided a print TN for the teacher she/he the read the TN to the student. This would get the student familiar with the concept of keys. You could then braille all the questions related to shape and colors. You could then present all the shapes again with the button holes followed by the questions for button holes.
Just my thoughts ….” This person later recanted and said that none of the buttons could be omitted.