ethical issue

So, we all know that we work ourselves to the point of exhaustion and sickness....I reached that point the other day. I work in an ECF and the night was just one of the worst i have had in a long long time. By the end of the night i was feeling very nauseated and wondered if i could call my doctor and just ask her to call in an order for me. I asked the other nurse on duty if she thought my doctor would comply. She actually looked at me and told me to take some off the cart. She brushed it off to say that the medicine wasn't of much importance and it wasn't like taking narcs or other meds used for specific diseases. Don't worry, i DIDN'T take it off the cart, but now i'm wondering more and more. There had been rumors flying around about this nurse and how she supposedly had been fired from other jobs for stealing meds. Of course i had heard it and got just as much amusement from hearing it as everyone else did, but i didn't actually believe it. I mean we all know how the gossip mill works....most of the things we hear only have a tiny bit of truth in it. So, now i'm pretty convienced that those rumors may have more truth in them. Now i do work with this nurse fairly often. Everyone that follows her complains about her, but she is an RN for several years and an LPN many years prior to that....and i'm a new grad LPN with about 8 years of aide experience....so most of the time i just don't question the things she does. I do what i need to do and if she needs help i help her, if i need help i ask for it. I NEVER give her my keys (thank god i don't do that with anyone) but i'm starting to become paranoid. What is my obligation here? should i report it? i mean it wasn't like i saw her take anything or that i've ever seen anything done wrong. She's done things differently than i would have on many things, but i just always say "i'm the new grad." but i just don't want to be in a situation where things come up missing or because i work with her i should "know what she's doing all the time." any suggestions on what i should do to CMA (cover my a**)