In Sophocles' Antigone, what is the implied impact of the invisible woman, Jocasta, on the community and the characters?

Jocasta is implied as having
had an impact on the city of Thebes because she committed an act that is said to have
poisoned the land. As we learn in the first play of the
trilogy, Oedipus Rex, Jocasta and King Laius were given a prophecy
that their son would kill Laius and then bed with his mother. Fearing the prophecy,
Laius had Oedipus bound by the ankles and ordered for him to be killed. Jocasta gave the
boy to a shepherd who was supposed to abandon him on a mountain top but instead gave the
boy away to be cared for, which resulted in the fulfillment of the prophecy. One might
say that Jocasta is blamable for not having had the boy killed properly. But even if she
is not, she married her son and committed incest, which is immoral in the gods' eyes.
Any immoral or impure act was considered to
be poisonous to not only the people who committed the act but also to the
rest of the community thus bringing more and more grief and
hardship. Hence, Jocasta is implied as being responsible for the hardships named in
Antigone, such as the death of both of Jocasta's sons and her
daughter Antigone.

Ismene particularly reflects on all of the
tribulations her family has suffered due to her parents' transgression when she reminds
Antigone of how many lives in their family have been lost, begging Antigone not
jeopardize her own life as well by breaking Creon's decree. We see her reflect on all of
the deaths of her family in the lines:

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Think, my sister, how our father
died
hated and infamous from offenses
self-detected ...
...His wife and
mother--
both words at once!--took her life with twisted
noose;
then, third, our two brothers in just one day
slew each
other. (50-56)

The phrase
"offenses self-detected" refers to the fact that Oedipus figured out that he had
fulfilled his prophecy by killing his own father and marrying his own mother, and
"infamous" refers to the fact that he died hated because his deeds polluted the city,
showing us how both Oedipus and Jocasta have an implied impact on the characters and
events in Antigone. In addition, Ismene's reference to Jocasta being both Oedipus's
"wife and mother" also show how Jocasta has an implied impact on the
city.