Your concept is a very nice, classical goth theme that holds a resemblance to well known artists such as Victoria Frances.
All pieces you have used fit theme-wise perfect together. I like how you composed the image as well. The balance between your character and background elements is very harmonical and calm without being boring. Your light is very untypical for this genre, which let your composition stand out more and adds your personal style and fresh view to the often very dark goth artworks. Your color sheme is simple beautiful.
But I think that you could work a bit on the shadows to make everything look more natural. The candles in her hand should have a kind of "glow" and if your main light comes from above it would be a nice effect to darken the bottom of the picture and parts of your main figure a bit (more than it already is) and add some highlights to f.e. the hair to raise the dramatic in your lights.