I don't have anything on candle wax. But here is my attempt at a candle lit effect:
I used a tungsten Fresnel spotlight camera left, and very slightly higher than Bella's head to just skim past the candelabra (best buy I ever made at a flea market). The tungsten light is close to the color of candle light (of course, since these are electric candles they are exactly the same color I guess). Since candle light would be considered "hard" as it's a small source, yet very dim and flickering, I also used a Zeiss Softar filter, then painted in local contrast to enhance detail where wanted (eyes etc.) with Topaz Detail.
Then, dodged and burned in Adobe Camera Raw, and finally used a curves layer dropping the overall illumination way down and painting back the light where I wanted it with a soft black brush set at an opacity of around 7 or 8 on the curves layer mask.
In John Altman's book, "Painting with Light" he describes the way they did it in movies back in the 30's by constructing an artificial candle with an electric light in the side facing the talent. I've bought a small dome slave strobe to do the same with a candle today but haven't gotten around to it.