Dreams involving family members, especially in a joyful context, can often reflect your feelings about your relationships with them. In this dream, your mom's happiness while driving you to school suggests a nurturing and supportive role she plays in your life. School often symbolizes learning, growth, and new experiences, so being taken to school while feeling sick might indicate that you are facing challenges or feeling unwell in your waking life, whether physically or emotionally.

The happiness of your family in the car could represent feelings of support and encouragement despite your current struggles. It may also signify that you have a strong support system that you can rely on, even when you're feeling down or unwell.

Consider reflecting on your relationship with your family and any current challenges you are facing. This dream may be encouraging you to lean on your loved ones for support as you navigate through difficult times.