In A Farewell to Arms, how is Catherine Barkley a code hero?

This is an interesting question for two reasons:
Traditionally, Hemingway's heroes are male, and many reviewers interpret Catherine as an
undeveloped character in the novel, merely an idealized projection of male desire. Upon
closer examination, however, Catherine does share characteristics of the code hero.

Hemingway's code hero is a skilled professional; Catherine
is a nurse who is skilled in her profession. The code hero lives with courage in a
dangerous world; Catherine demonstrates courage when she and Frederic row across the
lake to escape into Switzerland, a very dangerous feat, and especially when she tries to
deliver their baby, finally realizing that she will die. The code hero lives in a random
universe, but chooses to control himself and endure; Catherine cannot control events
when she goes into labor, but she endures the pain with dignity until her death.

Catherine endures in other ways, as well. She experiences
the death of a fiance, faces great fear as an unmarried nurse when she learns she is
pregnant, and suffers enormously when Frederic leaves her to return to the war.
Throughout all of these trials, however, Catherine does not feel sorry for herself, and
she does not break. Like a code hero, she endures.