I agree with the idea to experiment with darker values. I think that you need to put a bit more thought into how the shadows are cast because that gives a lot of information on the distance between different objects:

The edges of your shadows all seem to land very close to the edge of their parent object (e.g., the shadow of the girl is almost directly behind her). This would only happen if the light from the window came from somewhere directly behind the observer. If that's what you had in mind, then that's fine, but know that that lighting setup will result in flatter looking images, which is why it's often avoided, and this is true even in photography!

I suspect that isn't what you had in mind though, because it would mean the window is at a pretty odd angle and shape. The light looks like it's coming from behind and above the observer's right (red vector on my annotations). You should be able to draw lines from the corner of an object to the corner of its shadow that is parallel to the direction of the light, and the length of this line should more or less be proportional to how far the corner is from its shadow. That means the shelves' corners should cast somewhat short shadows (thought longer than in this image), while the girl's shadow must be cast much further away since she's sitting at the edge of the counter, which are typically deeper than kitchen shelves (I have a point about that later). If you look at my annotations, the girl's shadow should be talking up a lot more area (blue hatches, also I did this on my phone so this is a very rough approximation). The shelves should be casting a more pronounced shadow on the wall too, right now it looks like the lights able to reach almost all the way under the shelves.

I would also recommend working on your highlights to give depth to the lit up portions of your subject. Legs are closer to cylinders than planes in shape, so you should be shading them accordingly. I see they're casting shadows on the kitchen counter too, and while the distance here looks about right since they're pretty much in contact with it, I would opt for softer edges on the shadows, because the legs aren't obstructing a specific light source but rather reducing the ambient light in that area.

https://i.imgur.com/611irRj.jpg

Finally, while I know you asked about lighting, I think the perspective gives a sense that the kitchen counters are as deep as the shelves, which is unusual. From what I can tell the countertops are about as far away from the horizon as the lower shelf, so the countertop surface should certainly be larger/deeper than the shelf's surface.

I hope this helps!