A user on another forum was looking for this story. After reading his description, I'd like to see it as well. He said it might have been titled "Flux".
The story was about a single mom whose son developed a sort of technology. Long story short, the mom was able to steal height, strength, breast size from people, but only got a 10% of what she took. So she was shrinking people to miniscule levels to get just a few inches of growth. After she gets control of the technology, she goes after the other people who helped her son develop it so they can't stop her, stealing their height and strength and killing them in the process.
Thank you for your time.
