She is just exploring what her body can do. She is probably also enjoying what you are doing. I taught my kids to wiggle their tongues back and forth when they were that little. They were the life of the party most of the time because everyone thought it was so funny. By no means was it a sign of disrespect. It was just silly fun watching their little tongues move back and forth. I don't think you have anything to worry about. It is a good thing she is mimic what she sees.