Thank you for all of your comments! I love knowing that I can turn to YT when I need advice.
As far as I know, her anal glands have never been expressed unless the groomer has did it and not told me-but I doubt that. She's a little over a year old. Dry kibble is all that she eats so I had assumed that her "hard poo" is taking care of it. I WILL be looking for those tapeworm segments though.
Currently, I am pleased to report that the butt-scooting has ceased and she is peacefully napping at my feet. We'll see how long that lasts!