If your child brings a problem to you, consider this an opportunity to model positive problem-solving with them by working with your child to come up with their own solution and talking about how to work with the teacher to resolve the issue. You could use prompts like “What if we ask Mrs. Penny if she has any ideas about how we can sort out this problem?”, “How do you think we could start this conversation?”
If something has happened that has upset your child, it may upset you too. Take a moment to understand the situation and calm down if you need to. This will help to avoid doing something that might create more difficulties later; like sending an angry email or giving your child the wrong information. Ask for advice from someone external to the situation if you need to.