Identifying psychosis

Hi, I’m new to the forum so apologies if I’ve posted this in the wrong place.

My best friend has schizophrenia on both sides of her family, including her mum, and recently told me that during a recent period of significant stress/depression, she had some hallucinations (visual and auditory), although they were brief, and while they seemed real to her, she could also recognise they were not. She’s in her mid-late 20s so i understand it’s prime time for this to start manifesting. She’s very high-functioning, independent, does well at her job and generally takes good care of herself, so I feel like any changes in her personality should be easy to spot, but I do want some advice on things to look out for if this sort of thing comes back. She feels sure that if they came back again she would seek help, but my understanding of schizophrenia is that the person feels the hallucinations are real, and so she may not recognise it in herself. She has always been there for me through my own mental illness so I want to be prepared to help her as best I can if something happens.