LPN turned RN got full time, no posting!!

I could use some help, I am a PRN RN with my employer on a unit where an existing full time LPN who passed her boards was offered RN full time hours. While this is great for her, my boss did not post this "created position " with the hospital system. Can anyone help me find out if there is help ? I have been looking for a position in this unit, and am puzzled as to no chance to interview, as the position was not made public. I work for a large hospital system. Hospital politics and procedures on hiring is not my specialty, but I think I have been shafted, out of an opportunity I would haved liked to have pursued, please help