You appear to be shooting with the flash on-camera, judging from the position of the catchlights in her eyes, and the angle of the shadows. For a direct flash photo, the appearance is pretty good. However, your flash head is close to the lens axis, and that generally gives "flat" lighting as the shadows are almost invisible.
As you learn to control the flash, you will find that putting the flash off-camera will give you better detail definition because the shadows will help define the shapes.
Another factor to controlling the light, is to know that small light sources (bare flash, direct sunlight) cast harsh shadows, while large light sources (open sky, large reflector, softbox) cast soft shadows. So while the initial primary goal of using flash is to get enough light to get a decent exposure, this is quickly followed by the need to position the light to create the detail-defining shadows, and to modify the light to manage the hardness/softness of the shadows.
Bare flash on camera works well, however, when used in fill mode, where the flash exposure is throttled down by 2-3 stops (via flash exposure compensation feature). This then doesn't add light to the highlights, but does fill in the shadows to a certain extent.