What is Susan's dilemma?

Susan is faced with the dilemma of say something now and get fired (ie: accomplish little but do what's right) or put up with what is happening in an effort to change it when you are in a position of power.

Susan's risk evaluation based on priorities - provides justification for her actions

Risk of being ostracized and/or losing her job

Risk of allowing people to continue stealing and becoming part of the problem

She has to stand by while no one does anything to correct the problem that she knows is wrong. As a result, of poor management she is left with a decision to make. While her intentions are good she is not sure what is the most effective route to take to accomplishing her goals while still keeping the position.
There is an element of self interest in this case, as with many ethical dilemmas. Susan could approach the co-workers and demand that they stop, this would turn the group against her and eventually be forced from her position.

Alternatively, she could wait until she becomes a manager to change the actions but that would require her to "allow" the activity to continue. This creates a significant dilemma because she must sacrifice personal gain for her employer. She attempts to rationalize "allowing" the action as the best route to changing it. This also provides her with a stable job and the justification sheds light on how she weights her priorities.

What influences her perceptions and behaviour?

She is influenced by management's decision to" ignore" what is happening. She understands that the owners may not be aware but focuses on the positions that have direct authority on the students and workers stealing. While she has no power herself she believes that with a supervisor position she can use some force and change the actions of the group. Therefore, she has rationalized the problem to be a