Purple ball

I bought a purple playground ball for Kendall thinking she'd like to bat it around the back yard and chase after it as other dogs in my life have. Well, that hasn't happened. She runs around and around and around the ball. She barks at it occasionally but mostly runs around it. It's funny when the ball drifts around the back yard with the wind. She thinks it's after her. She doesn't seem afraid of it but doesn't want to play WITH it, either.