I'm VERY surprised to see a school giving grades to a 1st grader. I've never seen that around here.

I would not be too concerned about the grades themselves. For kids this young, teachers are not going to give tests or assignments that are so difficult that many kids would get low grades. I'm sure that tests and assignments are designed so that most kids will be successful.

That doesn't mean you shouldn't be concerned about things being too easy. But in first grade, I don't think you need to push to find the ultimate challenge in every area of study. I would see if you can increase the challenge level in one major area. And don't forget that you can provide challenge outside of school and outside of academics. It's not all going to happen in the classroom.