Perhaps you should shop laughing and start listening...

1. 90% of the rest of the world has no idea what we do. It's all magic to them. But they're not dummies. So when they say something ridiculous, we should help them, not laugh at them.

2. Most of your future customers will (obviously) come from that 90%. If they sense your attitude, they will take their business elsewhere.

3. Their fears and ignorance = your learning opportunity about your market.

4. She's your aunt, for crying out loud, and she actually bothered to email you. Show a little compasion and be glad. Lots of us never hear from our relatives.