Hard Head/Made of Iron: Her response to Alej smacking her in the back of the head with the butt of a rifle so hard the rifle snapped in half? Mild annoyance.
It seems to be a sign of her Narakhan heritage.
Hooker with a Heart of Gold: Back when she was hunting down her Disappeared Dad on her own, she used to "work" (read: as in "working girl", a euphemism for "prostitute") to pay for her living expenses. She's not proud of that part of her past.
Foil: To Mora, arguably. Mora had most, if not all, of the aspects of her good life given to her on a silver platter. Rachael, by contrast, had to work tooth and nail her entire life just to survive, much less live a good life.
Walking Spoiler: Her very existence is tied to a key turning point in Alej's growth.
Traci “Tiggs” Biggs
Ascended Extra: Her first appearance had her as part of Miles' college backstory. She became impressed and attracted with him for speaking out against a professor, and later slept with him. She's become a far more unique and developed character since.
Sugar and Ice Personality: Defintely not in terms of romantic love, but it's clear she knows how deep the relationships between Nanozells and their owners run. Really, she's perfectly pleasant when she's not around jerks (i.e., Miles, Vixy)