First off, I have to say, the coloring is amazing. Your choice of tone and hue works very well together. With this being Lilith, I would assume the dark colors red and black. You did a very nice job with it. I can see your shading, but its unobtrusive. It is a little too subtle in places and could use with some greater contrast with shadow to highlight. Never be afraid to add intense darks. It can serve to really highlight the other portions of the painting/drawing.
I don't know if it's intentional, but my eyes are really drawn to the wings first then the fire on her hands, and finally to the red on the twins next to her. My eyes follow the flow of wings to Lilith to the left twin then to the right and back again.
I can see what you are going for with the poses, and for the most part you did a terrific job in keeping it natural. One part of Lilith's pose that grabbed my attention was her raised shoulder. I'm not really sure what's going on there. If you keep anatomy in mind, a raised shoulder like that with no effect on the body means it's detached. There's usually a line with the shoulders and with this drawing it seems arced. I would make the suggestion of looking at some anatomy so you can see the subtle shifts that happen when someone raises a shoulder like that.
The other part is her legs look very straight. It's fine if that's what you were going for, but it might help to add some curves and softness to her legs. Like with the muscle on the thigh. It looks virtually straight yet naturally it has more of a curve to it. At the knee, looking from this angle, I wouldn't think you would be able to see it bulge like if it were from a profile view.
The posture with the twins looks great. The way you have drawn them makes them appear as if they are floating or gliding along which is an amazing effect to capture. It is difficult to accomplish. I applaud your skill.
Looking at the twins, the tail behind both of them from looking at their size and posture, it almost looks as if it were coming from the lower to mid back. Now, I can see with Lilith that the tail is coming off of the spine. The curve of the tail, if coming out of the clothing, would need to be changed slightly. It would need a different curve than if it were coming straight off the body to make it appear as if it comes from within the clothing than attached to the clothing.
I'm searching the painting for things and I keep finding the detail you put in. With everything you added to Lilith, you truly made her the center of the painting and not just from her position within it. I'm looking at it and noticing more and more details that you put in, like the second set of wings. I almost missed them completely. Perhaps, darkening behind the second set or adding alternative highlights will bring them out a bit more.
The wing position is fairly common. A lot of people hesitate because wings intimidate them, but you went on and did a fantastic job. You added in the detail needed from line, color, shape and tone to make them really stand out as wings. There's no confusing what they are. I can see the overlap of wings, such as with the right twin. It makes me think you are including them rather than adding them as a backdrop or just thrown together. Wings are complicated to begin with. You certainly worked hard on them.
The coloring is well chosen for the wings on each figure in the drawing. Seeing each one fully outstretched can make them seem repetitive. Perhaps, adding some variety to wing position will make it more natural and realistic/believable. When it comes to the coloring, I am a tad confused. Did you choose the membrane in between the 'fingers' to be dark or is it shade? If it is shade, I would suggest altering that a bit. There would be no way light would fall on every single portion of wing the exact same way. If it is purposefully dark, as in that's the true color it is suppose to be, I would suggest adding in more midtones. There are many dark spots and light spots on the wings but the midtones, which have more range, have fewer than the others. It's difficult to apply them in a situation like this but perhaps changing the tint and saturation will help. Having a washed out shadow looks better than just black. By adding in the midtones, you would create a picture where the darks and lights stood out more.
The background you chose doesn't subtract from the drawing at all. It seems to push the figures to the foreground establishing them as the main component the viewer should be looking at.
I'm looking over your picture and loving the whole aspect of Lilith. She has this power game going on supported by the two next to her. Her pose was well chosen as it make her appear to be striding with confidence. The spikes you added to the tail look like a formidable weapon when the timings right. The horns on her head are twisted nicely. The fire in her hand is believable but not generic or over done.
The picture has nice balance and composition. Each aspect of the drawing has had attention to it. THe only other thing I'd say to pay attention to would be the energy of each movement. (I have an interesting time with it too.) It can be hard to capture the exact energy of each motion. I find that gesture drawings really help in capturing the feel of the pose. You did a great job and have really improved on your poses. The pieces of the drawing aren't lightly added. Each part looks very well don. I'm very impressed with the drawing. Great work.