Curious to see how this panned out.
Sorry this happened OP. For future readers, in this situation I'd recommend clearly identifying your roles/responsibilities and doing your job, not theirs. Is your job to complete tasks/follow-up items on these 10 patients as an intern? OK do that. Obviously, there will be some cross-coverage items during call but it's not your job to do extra work to do or dig so you can give your night intern formal presentations on patients. If your co-resident doesn't give you a good sign out to you, your job is to write down what they say even if it doesn't make sense. If it's incomplete, don't spend time digging through the chart because then your work will suffer. If/when night float who has never worked with this person gives you grief, just state that that "I was told": and verbally say what your colleague verbalized to you. Answering nurse pages during cross coverage is more annoying because RNs don't care about our dynamics just like we don't care about theirs when something isn't chart and in those situations look into what's actually going on and use that to augment your sign out. Ex: "I was told to follow up HgB on 609, I was told it was last 8 but the nurse called me because it was 6.8 in the AM so I ordered a unit of blood because this patient is admitted for ACS", please follow up and transfuse for a goal of 8. State the facts. Don't editorialize. If the night resident becomes rude, just be amicably but then report what was said to your senior with your perspective. As an intern, it's not your job yet to be accountable for bad co-interns.
Most residents by default don't act like this resident. What you don't realize is that word travels super fast and in residency, when one mistake is made, people key in to who made that mistake. If it happens multiple times, whispering commences. If this level of incompetence you've mentioned is present, the program 1.) already knows about the behavior 2.) may even have a political reason for not escalating the situation. It's not your job to try to escalate the situation or compensate for the poorly performing resident. You're just making your life more complicated than it needs to be.
The only unfortunate thing is that if she's always working with you, the attending/senior will clue in on her crap and not see your mistakes as a problem. Short term, that can be a good thing to demonstrate contrast and that you're a good resident, but simultaneously you need to make sure you're still growing as a resident.