Med errors, but not mine... HELP please

I have been toiling with this problem since I got home from work today. I work in home health care and I am the full day time nurse and there is a full night time nurse, both of us began this case the second week in May, patient just home from the hospital. In this time I have had several issues with the other nurse regarding her standard of care such as not giving a PRN med which the patient very much needed because she did not know what it was and did not bother to ask or look it up until 2 weeks into home care and I brought it to her attention. She is careless with items like suction catheters, leaves them lay and reuses, one day she pulled a catheter out of the trash to reuse it, does not ware a glove when suctioning the trach. She does not chart most of her meds properly on the MARS, when she charts them at all, so when I need to know when a PRN med was last given I have to go to her flow sheet and read down thru it to see when the last med was given BEFORE I can give it again. ( OK I am getting to my point ) When I took these problem to my supervisor she said she felt like this other nurse was having neurological problems and does not make transitions well from job to job and to give it more time and she would speak to her.. OK I said. But this week, while looking thru the medicine sheets today I noticed that the other nurse has been making med errors by over dosing with the patients Ativan, and Tylenol : ( too much too soon) and giving a couple other meds too soon together also and this has been going on for at least 4 days that I know of, ( I did not go back further than the past 4 days). So, I feel like I should go to my supervisior again, and I know I am going to feel very angry if she does not do anything about it.. I personally don't feel like this other nurse should be in a unsupervised atmosphere like this one. She makes SSOO many sloppy mistakes and now this. I also believe, as I recall that it is my duty to report things like this.. ??? even though this is a first for me. I have never had to work "with" a nurse who has made so many careless mistakes before and it is really going against my grain. It is very frightening and nerve racking to go to work and not know what delemma I am going to encounter of this type tomarrow. It is stressful enough to take care of a patient with special needs: et:

G tube. trach, breathing problems, head injury who is bed ridden without having to keep my eyes peeled for this sort of stuff. And I am fearful for my patient, very fearful. So, do I approach the nurse or go to my supervisor again, with the possibility that my super will think I am just harrassing her and tattling about this nurse who I definatley dont believe belongs in this home?? ..... HELP...Sleepless tonight!!!