Seems ok for a start, but there should be a 3rd frame with her just stopped so the animation will run smoother. Also, regarding your sprite, you should put shading into it. You should be able to find some tutorials online about shading. Obs. Her arms should also move along with the hands.Keep it up though!
Agreed with Casdak7, and I wanted to add to not forget that when walking naturally, each arm swings with the motion of the opposite leg. Check out the attached image I grabbed from Wikipedia.