Order food where she wants to eat for the both of you and and down and have a come to Jesus moment with her. Tactfully, lay out your expectations of her that coincide with her job duties. Sometimes, ppl have expectations that others justify not having of themselves. They fall in to habits that sometimes they inherited from the poorly performing preceptors they had. I can't remember if you said you did or not, but if you do not say anything....if you are not direct in what you like and don't like (even though they should know better!) you can hold them accountable until you hold yourself accountable first. Do not go off assumptions that you're on the same pg but she she simply just wants to write her on page in a book that's not hers.
Tell her, the little old ppl she cares for DID NOTHING WRONG, BUT GET SICK. They saved up 50,000 to but because low end LTC is at least 5,000, that money is gone in 10 months. If I'm paying 5,000 a month I WANT QUALITY SERVICE, don't you?? Somebody tells them when to eat and go to bed and they wait on others to help them if they mess their pants. We shower when we want. It's Thursday. They may be told they have to wait to shower till Friday. They have cared for others all their lives and they are at our mercy most of the time to help them. One day she just might be in their position. Let her know she is not in this alone...she is their to aid you in caring for them and you appreciate her...you couldn't run the unit without her. (By the way, the best ran units are the ones that have CNAs/Techs who think they are running the show. Give her that if you haven't already.)
Do you two talk about your personal lives at all? What I'm getting at is maybe if you work to build more commeraderrie with her and other CNAs in the future it will also build in them that drive to at least want to help you and be around even if that drive isn't their bc of motivation to simply help pts/residents the best way they know how. Sorry for the poor analogy but it's almost like a mommy daddy relationship were the closeness of you two dictates how well you take care of the helpless ones under your care. You're a not a team but that doesn't mean you can't be tonight...or the next time you work. Encourage her by letting her know that a job well done may make her feel good even better herself....it will give her a sense of pride and dignity in a job well done. Be willing to compromise. Let her sleep on her freaking BREAK. It's her time off the clock and she is of no service to the job, awake or asleep. Maybe you already do, but I remeber when I was a CNA, when a nurse jumped right on in and offered to help with a few pts during a round (under the guise or sincere intention of just wanting to see how the pts/resident's backside was looking ) my respect for them sky rocketed. At the same time, I genuinely cared about the residents/pts I took care of. I'm sorry you're in this situation but it will not last for ever and you will get through this.
I'm just throwing out ideas....you can throw them back.