Now that's one cutie right there!
Because this is pretty minimal everything needs to contribute to a directional light source. That includes your colored outlines. The bun in the back has a very light top, but the outline for the rest of the hair and face is dark, and gets lighter towards the bottom, so it's as if light is coming from below in the front and above in the back. Then there's that "refracted" light in the color of the hair on our left side that's muddling it, too. And yet still, your cloak is light at the top, but the outline gets darker as you go down. You have something going on with the pants, but if it's not just a stripe pattern and is supposed to represent shading below the knee, it's too high on the leg, but shows directional light from the front and above as with both the belt buckle and what the cloak possibly suggests. And then the shoes have light coming from either side there at the bottom.
Once you focus your light source, your shading will fall into place. Think about where you want your light coming from, make an easily recognizable dot off in the ether to represent the source, and imagine that ray striking from that direction. You can draw directional lines if it helps you more visually zone.