Strange Betta Behavior?

I recently won a tiny female betta from a carnival. In her tiny plastic container, she sat mostly at the bottom leaning on the side of the container. When I moved her into a larger tank, she swam around vigorously for a bit. Now, she still keeps close to the tanks side, near the top, and seldom moves. When she does move, she sometimes backs up, so that her tail is up and her face is closer to the ground. Is this normal behavior?