First comment I have is that if you want us to critique your photos, I would for sure upload them somewhere else besides facebook. FB absolutely murders image quality. I have no doubt that your image actually looks better than what is posted on facebook, so for this quick review I will try and take this in to account.
For the first shot I will say that trying to fake an image taken during the day to make like it was taken much later or in a dark situation is something I find incredibly hard to fake. I really wouldn't know what my best suggestion would be hear, but if you really want it to be darker, I would do that in camera
As far as the lightening goes, you are missing one key factor in making it look realistic...and that is the brightness. If you actually took that picture, the lightening would be completely blown out (i.e. pure white) and only the edges of the bolts would glow the color. Also, because this would be so bright, it would become a secondary lightsource. I would have used the dodge and burn tools to give the appearance that what is in her hands actually has light that is effecting everything around it. Because of those two things, the effects don't line up with the rest of the image, and the result is what looks like someone taking a downloaded photoshop lightening brush over an image XD
I will try and do a quick critique on the other image when I get the chance.