The best thing you can do is talk with her teacher. If your daughter needs extra help It or instruction, the teacher or a resource person from your daughter's school can give her some extra attention. It is not uncommon for students to get pulled out for extra help with reading or math.
If she brings home an assignment and is struggling with it, ask her what she remembers from school that day. What did the teacher do in class? Did the teacher give them an example? If her class uses a textbook (My son is in 5th grade, and they do not. They just bring home workbook pages.), have her read that section to you and explain it to you. If she does that, she should be in a better position to handle the homework.
But definitely talk to her teacher.