Sojourner Truth most likely included paragraph 2 in order to:

a. Illustrate the injustices against black women in the South.
b. Show that women need help from men.
c. Emphasize how slavery dehumanizes people.
d. Demonstrate how polite men behave in the South.

That man over there says that women need to be
helped into carriages and lifted over ditches, and to
have the best place everywhere. Nobody ever helps me
into carriages, or over mud-puddles, or gives me any
best place! And ain’t I a woman? Look at me! Look at
my arm! I could have ploughed and planted, and
gathered into barns, and no man could head me! And
ain’t I a woman? I could work as much and eat as much
as a man- when I could get it- and bear the lash as well!
And ain’t I a woman? I have borne thirteen children,
and seen them most all sold off to slavery, and when I
cried out with my mother’s grief, none but Jesus heard
me! And ain’t I a woman?