How would you characterize the philosophies of life at which Adah, Leah, and Rachel arrive in The Poisonwood Bible?

Barbara Kingsolver weaves the theme of each girls'
different approaches to life all throughout the novel.  She leaves a trail of symbolic
references.  Take for example Rachel's reaction to the ant infestation; she says
she

"stuck my
elbows very hard into the ribs of the people who were crushing in around me, and kind of
wedged myself in...instead of getting trampled I simply floated like a stick in a river,
carried along by everyone else's
power."

This is indicative of
her entire approach to life--don't ruffle feathers, let everyone else do the work, and
take the easiest, most convenient route to comfort and prosperity.  Later, she describes
herself as "the Fourth of July," to reflect her rather sparkly, noisy personality. 
Earlier, in listing all of the girls, Kingsolver uses the phrase "carry us" to describe
Rachel; she lets Axelroot and a series of other marriages and circumstances carry her
about and determine her destiny, just as she did with the ant situation.  She is also
the "lock" of lock stock and barrel, because she locks on a way out, and takes it.  It's
just easier that way.

For Leah, she is described as "marry
us," to symbolize how she takes Africa into her heart, and essentially, marries Africa
and its causes, making them forever her own.  She is also described as "day," because
she is straightforward, bright, and proactive in her approach to life.  Later, she is
described as the "barrel" of "lock, stock and barrel," beause she "barrels forward,
setting everything straight."  She is aggressive, takes on other people's problems, and
fights to fix them.  She is a bright force for positive change, and takes it all on
herself.

Adah is an interesting one; she is "night,"
because of her dark cynicism and inward thoughts.  She is a bit cryptic and depressing,
and plays the role of cynical judge for everyone else's behavior.  As she says of
herself, she has great flavor because she is "spiced with the flavors of vice," or bad
thoughts.  She is the "stock" in lock, stock and barrel, because she "quietly takes
stock" of every situation and analyzes it.  She also is ferried out of Africa, helped
out, and eventually comes into her own.  She is a deep thinker, an analyzer, and
approaches life slowly and with forethought.

I hope that
those thoughts helped; good luck!