It's a very nice looking character (reminds me a bit of Roxy of Gen13, she also has a purple streak in her hair).
As for design : you're using shading. This can create depth but can also destroy it just as easily. When I saw the animation it cried out "flat" to me. That's because the shading doesn't change on the tilts of her head. Now, this might actually be a deliberate choice and an effect you want to achieve. It has its own dynamics (on a minor note : the highlights in her eyes seem to dance between 9 and 12 o'clock, this will only happen during major movements).
The hair springs nicely on her steps (which I like) suggesting fluffy hair. But when she tilts her head, it doesn't hang down with gravity, it keeps following the same arcs as if fixed in place with loads of hairspray. I think it's an important decision to make whether her hair should be fluffy or stiff. She's your main character and animating that hair on each movement will take time.
Talking about tilting : the shoulders don't really react to the tilt of the head. Each movement of the head should be facilitated by the shoulders. Making the head move without an appropriate response of the shoulders will make it look stiff.
The motion of the walk is a bit jerky. It shocks too much and, at places, there's a tilt of the entire chest. Now, shoulders and chest don't tilt really that much in a relaxed walk (shoulders roll along counterwise with the hip movement, it's not really that big of a movement in a normal walk).
Imagine a line running down the chest and where it will end up down at the hips. This tilt needs to be counterbalanced by the hips. Try this : just stand straight up with your weight balanced equally on both feet. Then tilt your chest slightly and see how much your hips move the other way. The same goes for the head tilts. Just try them out and see what your shoulders do.
Now, if you look at animation movies that where made at a tight budget (not some Disney movie but something like Transformers or Pokemon) then you'll see that walks where only the head and chest are shown will only have that head and chest move up and down. No shoulder tilts, at best an arm that swings back and forth in 3/4 views and nothing of that in full frontal view. Having Ash Ketchum holding the straps of his backpack is pretty convenient, the arms won't need to swing, not even in side view, just slap some walking legs underneath him and make him bounce
This means that the up and down motion is the most important thing in animating a walk because those low budget movies get away with just having a single drawing bounce up and down for 3 seconds and it will still read as a walk to the audience. Of course, you'll have to draw attention away from that it is a static drawing. This is done by not showing it for too long (such shots are hardly over 5 seconds long if nothing else happens like talking), making the character advance towards the camera and making that single drawing look nice (with shading, for example). It seems to me that in such movies, camera moves are often used to draw attention away from the fact that we're looking at a single drawing for a couple of seconds, quick cutting also keeps our eyes from getting bored
In the end you need to decide what you really need to tell your story. I assume you're animating this on your own. Do you really need subtle and fluent shoulder tilts in that shot or can you get away with a single drawing which bounces and advances? Do you want realistical shading or do you want head tilts? If you want both then it will take a lot of time to get it right. You can also be creative with your shots instead. Show her advancing and talking the simple way (just a moving mouth, blinking eyes and for the rest just bouncing up and down), show the person she's talking to, then show a shot of her with her head tilted (perhaps two frames of the head arriving at the tilt and a bit of hair action following it up). Disney movies and books like that of Richard Williams or Muybridge show movement at its best. Cheaply made animation shows you what you can get away with (like 2 frame head turns) and still tell your story.
In the end it's all about the story. No bad story was ever rescued by a perfect walk cycle.