I did something similar with my speculative chart for Joanna - set up a noon chart and tweaked the birthtime until it seemed to 'fit', looked at lots of images and videos of her, read comments and quotes. I'm almost sure that the late Scorpio Asc is correct [her intensity and sexiness, the moles], and it puts Uranus [genius, eccentricity, collective mind] very close to the Ascendant degree, and the mighty Neptune/GC a little deeper in the first house, but still, y'know, upfront.
This, taken with the 12th-house Scorpio Moon/Jupiter and Her Sun/Venus conjunction, is a pretty full description of someone who has her sort of impact. I just wish I could verify the birthtime.