Assuming the EWR-CLT is a CO itinerary she is going to experience one of the most annoying bits of EWR-life - the Terminal C to Terminal A transfer. And coming in from the redeye there is a chance that the bus won't be running.

When she arrives at EWR she needs to go to gate C71. You can find that on the maps. From there she has to ride a bus to terminal A and then find here gate there. The good news is that the A terminal is tiny - all the gates are in a single "pod" so she shouldn't have too much trouble there. The bad news is that the bus can be annoying and might not be running at the crack of dawn when she arrives. And if she has to to the AirTrain route it will be much more confusing/difficult.

She'll get the EWR-CLT boarding pass in SFO. She can just show the second BP to anyone in a uniform and shrug her shoulders as though asking for help and people will help her out. It is EWR, but not everyone is horribly mean over here.