Agree with what she says; it obviously IS a "waste of time" planning to do something with you this weekend. But that is not a bad thing, it just "is"! You have your life and are living it the way you need/want to and that is all you can do. You are not here to entertain her when she comes around. Do not feel you have to fit her into your schedule instead of her fitting you into hers! You are just as important to any friendship as she is and, in your own life, should be more important.