See AM p.86 box: "In time, madness became a blessing.
Intellect gone, the spirit of the once-beautiful scholar prowls the temple, seeking any target for her pain. Her first priority is those carrying Christian symbols. Others, such as the scholars who failed to save her, the mob who killed her, and the soldiers who betrayed her, are all victims for the vengeful ghost."
It is not a technically clear text, but not a description of a person. You can of course just delete it for your saga and go on with it: I would do so.
Characteristics: Int +4, Per +1, Pre
+1, Com +2, Str –2, Sta +1, Dex
+1, Qik 0
Seems like the stat-block for a human. Also there is a reference to her ‘awareness of self’:
Powers:
Ghostly Body, 0 points, constant,
Mentem: Hypatia knows she is
a ghost and can ….
Given these, I would lean towards Hypatia being a human ghost. Others may differ; do what seems best for your saga.