My kids attended the Barstow school at the same time, and the last semester of her senior I drove her to and from school.
I can tell you this about her. She was always prickly, very eager to take stands on things that she knew would offend people. She wanted to burn a flag on the school campus, but her reasoning wasn't exactly clear. Just some sort of protest. The school told her no.
In her senior year, she submitted something that someone else had written to the school literary magazine. Unfortunately the student editors didn't realize it wasn't her work, but when the magazine was printed and distributed to the student body, several readers did spot the plagiarism. This was about a week before the end of the school year. The administration told her to clear out her locker, do not come back, and they'd mail her diploma to her.
She went to the the University of Kansas for her undergraduate degree. According to the internet she got a Master's at Portland State University, then her PhD at the University of Wisconsin, Madison. I kind of doubt she started passing as Black while at KU, simply because there would have been too many people on campus who would have already known her and would have seen through that.
It would be really interesting to see her academic records from all three schools and talk to people who knew her then.
I will say, having known Jessie during the years she attend Barstow, (8th through 12th grade) I am somehow not surprised she spent years deceiving people. It's also interesting to look at her ratings on the Rate My Professor website.