How is Blanche similar and different to her sister Stella?

One similarity between Blanche and Stella is their
background.  Both of them grew up and experienced their youth in the "old South" and
this imprint is on both of their characters.  How they deal with it, of course, is where
the difference might lie.  Blanche revels in this past, demonstrating an inability to
fully grasp how the function in the present.  It is in this context that Blanche tries
to battle with the present, even asserting herself against it, but eventually failing
and becoming victim to it.  Stella is much different, possessing what Blanche would
marvel at as "self control."  She is much more practical in understanding that there is
not much of a debate between the past and the present.  Human survival rests with the
latter.  Yet, she does show much of her own emotional compass in expressing a certain
regret for her actions regarding Blanche's institutionalization.  While she is very
practical about things and does what must be done for her welfare and that of the child
she carries, Stella does understand that there is some part of her past, some aspect of
that imprint, that still lingers in her and haunts her.  Perhaps she does not carry the
imprint in the way Blanche does, who was "too rare to be normal," as Williams would put
it.  Yet, it is there, that rareness, that abnormality beneath the sheen of normal
conventionality that is a part of Stella's emotional DNA.