When Helo shot Athena, the mother of the next race of sentient beings, and she downloaded on the Resurrection Ship, Caprica was there. To greet her, this third hero; not a Hero of the Cylon but a woman drowning in oceans of memory, who had been hurt by human and Cylon alike as much as Caprica or Boomer ever had, and still committed herself to bridging gaps. And simply in the look on her sister's face, Caprica knew her time on the Baseship was done. You never run from anything immortal, because it gets their attention, because their existence deforms the universe and our worlds merely turn around them. She snapped poor Boomer's neck, the false mother, to save the child; she escorted Athena and Hera back to the Fleet, her stomach turning over and heart racing, and stood in the scariest place in the universe, wondering whether they'd murder her. And back with the Cylons, her sister Natalie took her place.
She was manipulated in the brig by Laura Roslin, and learned to hate her; eventually she began to share her dreams: taking Hera to see the Final Five, in the truth of the Opera House. She never knew Gaius had had those same dreams and visions, long ago. Roslin took a crack at her programming, daring her to remember the Final Five. To remember that mother's love. She was visited by lonely, sad old Saul Tigh, who told her she'd never see Hera again. He looked older than her, but he was only a boy. He'd only had one false life, and she'd had ten thousand, every single one of those days directed toward one goal: purity and beauty, as cold and savage and bright and lovely as the forest cathedrals she projected on the world. Another green world, untouched by pain and history, ready to begin with something new.
Maybe it's academic at this point, but there's a pretty strong line to be drawn between the femme fatale and the belle dame sans merci. The first was an act, confusing for us as we got to know the angel wearing her face more than we ever knew Caprica herself; when Caprica returned to the Cylon she returned to the second. She remembered herself to herself, cut her makeup use in half at least. The thing about the belle dame is that she's more like Peter Beagle's Lady Amalthea than his Lady Celeno: perfection and immortality are cruel by their nature, they never come to it by malice. Malice comes later, when you fall to earth.
Neither of them knew, what he was to her. A confused, half-blind saint asking for succor from an enemy of the state; Lear leaning on Cordelia's shoulder, Antigone leading Oedipus by the hand. The frightened last unicorn trying desperately to bring a soul back to fallen Zeus, both of them with more memories stolen than the ones that remained. Saul begged for Caprica's help in turning off his emotions; she responded by turning them up to eleven. She beat him bloody and made love to him, and realized something new about the world. Another wall fell down. They'd thought a lack of God's love was what prevented them all from getting pregnant. She'd championed the idea, to keep herself from weeping at night, in her loneliness and jealousy, but having made the jump to the world -- having come willingly into enemy territory for the love of a child, having been given the gift of death by Natalie -- things looked different. Her heart had begun to sew itself back together. And the only thing she'd ever wanted, since that curious, bloody day on Caprica City and further, back to the mother she never knew she forgot, supplant that long-lost memory, and enter the world forever. She would finally be a mother.