I have had some success with very openly, honestly going to management and asking for their help figuring out how to get something done. For example, in this case, I would have gone to Helga’s supervisor and said something like, “Could you help me figure out a way to make this easier for Helga? She really seems to be struggling with it.” You come across as earnestly trying to help, but the supervisor gets the message loud and clear that Helga is incompetent.