Ania,
I only know my own kid and my own situation, so this may not apply to you, but i'll share my thoughts.
I would wait to say anything. First, you do need to respect that she is in her first year and is learning the ropes. She really needs some time to get grounded in the basics of the school and to set her class mood, rhythm, and style. Letting her do that is crucial to the success of her year. Second, you do not know yet if there really is a problem. He may get a lot out of the reading and assignments. But even if he doesn't, if his other classes are more demanding, he may appreciate a little breathing room. Third, at least for my child who is in the early stages of adolescence, I think it is important for children to begin to advocate some for themselves. I began to resent my mother advocating for me by the time I was in middle school--I wanted more independence and control and this is a good place to practice those things. There is certainly room for us to look out for our kids, but I think it is time for them to become more involved in deciding what is worth fighting for and what is worth accepting. If they want to change something, I would like to see them take the first steps, even if I come in to back them up later.
When DS is having issues with a teacher at the beginning of the year, I tell him to do his best work and hang in there of a month. The first month of school can be pretty chaotic and I like to give the teacher some time to get settled in. Sometimes the teacher makes adjustments by the end of the first month without us needing to say anything. Other times DS implies to the teacher that he would like harder work, and gets it. Other times we just decide the problem wasn't as big as we thought it was.
Also, what does Ghost think about all this?