Direct does not equal mean. If the OP's group is unanimous in their behavior, it will work. Just decide ahead of time how you will behave if you are asked for help. "Sorry, I am working on my own stuff right now and don't have time to help for an hour or so (or until break or until lunch ...)." She will go to the next person (after looking at you like a kicked puppy), and they need to say the same thing. When she gets to the "but it will only take you a minute," just repeat. I have always called it the broken record approach, and it really does work. If you aren't willing to confront the problem directly, nothing will change.