She’s A Geologist
It turns out that Melissa’s neighbors had seriously underestimated her. She was a very petite person, so they might have thought they could get away with making her life inconvenient, and she wouldn’t be able to do a thing about it. But what they had failed to remember was that Melissa was, in fact, a geologist. And that means she had access to a professional auto-chipper, which had the power to drill through stone and pulverize it in a matter of minutes.