Pick apart Kate Callahan's life and you get what looks to be a red-haired bushel of contradictions -- a Jewish woman who is sister to a Catholic priest, an aficionada of grueling Iron Man triathlons who loathes pain and suffering, and, perhaps most ironically, a cheerful, life-affirming soul dedicated to death and dying.

"My friends call me the closure fairy," Callahan jokes, of the inevitable conversations she finds herself immersed in at cocktail parties. "But basically, I'm helping people experience the most dignified, meaningful, love-filled, death and dying experience they can possible have, and if not them, then for their parents or grandparents."

For Callahan, born an 'Irish triplet' (she shares a birthday with two older twin brothers, one a priest), it's all about giving back. Growing up the eldest daughter of eight children in an Irish ghetto of Buffalo, N.Y., Callahan learned early both the sting of poverty and the salve of the Catholic Church community's close-knit support.

Married at age 19 but divorced when her son was five, Callahan earned an associate's degree in nursing from the University of Illinois before starting over in southern California, as a single mom.

Tooling around Santa Monica in a yellow Gremlin, she worked as a nurse, but later took a job as a sales rep for a hospital supply company, despite worry that Leaving hands-on clinical care for a more lucrative, but impersonal, administrative post marked her as an "ethical turncoat."

But, she...