How much should a supervisor expect from students who have graduated?
She might be panicking. Normally, it's good practice (though not strictly required) to hand-over such lab information in a well-documented process. It is a good idea to make a hand-over closing date (even with friendly people) to make clear that/when the process is finished (of course, you could help for isolated questions, but this should be the conclusion of the main process).

My suggestion is: create an overview of what you need to document and with which your task can be considered essentially complete. She cannot expect you to document everything - unfortunately, that transition would have had to happen earlier, with a newer research student. When a research student leaves, it is normal that know-how leaves with them, sadly. 

The fact that you write papers together lets this boundary blur, so you may have to pay a higher "tribute" cost to her if you want to maintain relations. However, I think, with friendly pointers to the precise locations where it's written and trying to promoting a habit of actually looking it up there, you may get somewhere. Some people have a hard time to follow rules of search for other people's work, and your task is to try to break that habit gently.