As a learning specialist and teacher, I have heard parents ask this question countless times. This is one of the few question to which I can give a simple answer:
However… your help has some parameters!
Help ONLY if and when your child wants you to help.
If she insists on doing it herself, let her. Later you can check in with her teacher to make sure everything is in fact being completed on time and to the level of quality expected. But in the moment, let her do it independently if she wants. And avoid a fight.
Help when your child is frustrated.
Or on the verge or melting down or panicking at the thought of not completing the homework on time. The next day, send his teacher an email explaining how you helped him and explaining that he may need additional instruction, guidance or practice on that topic or skill.
It may be a good idea to talk to your child’s teacher about homework at the beginning of the year. Ask what types of homework assignments will be coming home, what children are expected to do independently and what you should do if you child asks for help. Most teachers will tell you to let your child do homework on their own in order for the teacher to get a sense of the child’s level of understanding. If this is the teacher’s request, hopefully he/she is understanding when students come in asking for additional help and is flexible about extending homework deadlines if a child is truly confused.
As a parent, you are your child’s best teacher and advocate. Your instincts will likely be the best guide.