There's hubbub aplenty at this strip mall coffee shop in Irvine, Calif. A scrum of small children is being herded about by their barely-keeping-it-together moms and nannies, the sound system is playing Motown classics, and the espresso machine is hissing in one corner. Around Christina Levasheff, though, there is a palpable sense of quiet. She sits across a small table from me. Although she smiles softly, her eyes don't convey the same emotion. Pretty and vivacious, she nevertheless carries that vaguely haunted look you see in the faces of parents who have lost a child...