Monster Created by Previous Manager...

I would try to "pave the way" for your planned changes by easing her into the idea that change will be coming rather that hitting her abruptly with it. I would also give her a chance to have input into the discussion.

For example: I would arrange a semi-formal meeting with her and tell her that as part of your orientation to your new role, you want to get a sense of what her job is. Ask her to list her responsibilities and talk to you about what a typical work day is like. Perhaps you could even shadow her for a day (or few hours) to see what her work entails. Tell her in a pleasant (non-threatening) way that you will be needing to create a written job description for every employee and that's one of the reasons you need to get a good handle on her position. If you shadow for a few hours in the afternoon, ask her to show you what she accomplished in that morning so that you can get a sense of the whole day. Ask her about her peak times for workload, schedule, etc. Does she have what she needs to get the job done? What is most satisfying about her job? What is most frustrating? etc. In short, show her that you are assessing the situation and give her an opportunity to contribute to that assessment.

This first conversation and shadowing can give her time to think and to be emotionally prepared for some changes. You might get lucky and find that it is obvious that she is not working very hard. You might find a convenient conversational opening to point out that she has some "downtime" or "slow periods" where she might be able to help you/the unit with a few things. Her reaction to that "spontaneous" converstation might help you better gauge the situation.

Based on the results of that assessment, you can decide what to add to her duties ... or decide to reduce her hours. Work with your HR department to be sure you are doing things legally correct and in accordance to THEIR policies in case she protests. If possible, give her some options to choose from so that she feels she had some "say" in things. If you NEED her to work a consistent schedule, tell her that -- and tell her WHY. (If it is just that you or your staff resent the fact that her job doesn't require that she be there at a certain time -- that is YOUR and THEIR weakness, not hers.)

Finally, I am concerned that you seem to have already made up your mind that she/her position is a "monster" before doing an unbiased assessment. You seem to have biases about people who wear business clothes to work, have flexible schedules, are salaried rather than paid hourly, etc. If you are going to climb the career ladder in nursing, you need to understand that such people also do valuable, necessary work -- and not feed into the biases against such people that you and your staff may have. You need to hear her side of things to be fair. Even if your gut instinct turns out to be correct about her work habits -- don't be "out to get her" before you have given her a chance to respond to a little positive coaching. She may have valuable qualities/skills that you are not seeing because of being distracted by the negative.

I hope that helps a little -- but I certainly hope that you have a supervisor or mentor on-site who can help you through this process. The first time you have to deal with these sorts of things can be stressful.

I would engage another mentor at your facility or the CNO for advice. I would actually make time to "shadow" her to see for yourself the job she is performing. I would follow llg's advice to the letter.

In order to not come off as biased....I would try to think of her as less of a monster and work towards helping her become a more productive member of your team and vision for the floor.

I agree with consulting with your own superiors in developing a plan. There is a chain of command for a reason. :)