|It is a good sign that you want to review your own actions before signing off on this employee. The first place to look is at your description of the assignment that you called "fairly easy." In a real sense, that is easy for you to say, but it may not be for her. Because you saw the project as a simple one, it sounds like you did not provide her with adequate guidance and support at the outset and during the life of the assignment itself.|
Another issue is your reaction to her work. When managers say they were "pretty firm" with an employee, that is usually a code word for harsh words. The problem is that this type of treatment tends to cause employees to react with defensiveness, fear, or denial, none of which will improve performance.
When your employee performs poorly, try to look at yourself as a coach or teacher. Do not merely tell her that her work is sloppy, but try to show her more of what you expect. When managers model the behavior they want from an employee, they have a much better chance of getting a model employee.