wide walk is fine in my opinion
sometimes an extra tween is all you need.
note I gave her some extra hip sway.
Your animation is solid in its keyframes. If you're willing to put the effort to tween even a bit more you can get really naturalistic movement, but as you see sometimes even just a couple more stress tweens can push something from 'slideshow keyframe' to 'believable motion'.
EDIT: I guess the clearest point to make actually is that if you want to keep the timing you have now on the keyframes, you need to tween between them ALL once or twice accordingly. I made it faster and it looks better, but if you keep it slow, you need more visual information.