30 minutes to explain programming to a 15 year old [closed]

Question

I've been volunteered to sit down and talk about the life and work of a Developer with a 15 year old work experience student next week.

The catches are that

• I've got just half an hour, and
• I'll be just one of the people talking to her - other people in different roles in the business will also be running through the elements of their jobs with her throughout the day.

What should I cover, and what on earth can I hope to teach her in just half an hour?

I assume that she probably has no experience with development or programming.