If you’re going for a realistic look, then you’ll need to correct her facial features’ proportions, because her eyes are far too big for realism, with too little space between the eyes (distance between two eyes should be the width of one eye), and the right eye also looks crooked (tear duct side is dipping too low). Her mouth and chin positions are skewed too.
You are actually still using hard lighting, because the shadows are very hard-edged. I think maybe you’re confusing light quality with light direction. You have a hard lighting with the light source placed above and slightly in front of the subject.
Soft lighting means the edges of shadows are very soft with a smooth and fairly long gradation. If you look at photography lighting done with softboxes, you’ll see what soft actually looks like. Same with overcast days–the entire sky is a blanket of clouds that diffuses the sun into a very large and soft light source. If you need some basic knowledge on lighting, this is a great place to start: http://www.itchy-animation.co.uk/light.htm
To make hair look more realistic/credible, you have to to learn to depict the actual structure of hair. Hair isn’t like a helmet that sits on the scalp. Hair forms strands and layers, and you have to show how hair is actually connected to the scalp. When you paint highlight of the hair, you have to actually follow the structure and direction of the strands in a logical and smooth manner. You have many clunky looking brushstrokes that breaks the flow of the hair and that’s one of the reasons why it looks awkward.
One more thing–you have to get the epicanthic fold right for eyes, otherwise you’d change the ethnic appearance of the person unintentionally. Although Asuka is a fictional anime character, in the original character design she clearly has double eyelids, so you have to get that right.
Another area that can be improved, is how flat the forms appear. A face it not a flat plane with features–the face actually has anatomical structure such as eye sockets, brow ridge, cheekbones, facial muscles, etc. Her torso also looks flat, but I’m assuming it’s because you’re not finished yet.