The person in the video has lights shining on them (they are on stage performing) and the light is reflecting off their skin....looking very shiny and annoying/distracting.

In Kdenlive, is there anyway to try solving this? How could I get rid of that shiny light reflecting off the performer's skin?
Thanks in advance for advice!

If the highlights are not clipped (none of the RGB channels flat at 255), you might try bending the curves, to manipulate highlights.
This will of course affect ALL highlights.
If it is a very important shot, and you don't mind spending hours on fixing it, you could use rotoscoping to separate the offending highlights.

However, don't expect miracles...