Lolita Goth

Lolita Goth is a deceased Sim, who is an unknown member of the Goth Family. Her tombstone is located in the family graveyard along with her ghost.

Her exact relationship to the rest of the Goth Family is unknown, since she was never mentioned in any previous The Sims games.

Lolita Goth theories
Since she can't be found in the family tree, it is possible that she was not actually a relative, but simply shared the same last name as the Goth Family. It is also rumored that she was originally intended to be a relative of the family, but she was left out because the family could not hold more than 8 Sims.

One of the possibilities is that she is Frida Goth, Gunther Goth's sister. As opposed to Lolita, Frida has existed in previous The Sims games. It has been said that 'Lolita' is German for 'Frida', which supports this theory.

It is also quite possible that Lolita was the first wife or lover of either Victor Goth or Gunther Goth, which would explain why she isn't in the family tree though she shares the same surname. It may also help explain why Gunther and Cornelia had Mortimer so late in life; according to the general theory, Gunther married Cornelia after his first wife, Lolita, died. Maybe that's why Gunther does't have a good relationship with Cornelia.

It is possible that she is the mother of victor and in the sims she is dead in the grave yard in Cornelia's and Gunther's house

Another possibility is that she is Mortimer or Gunther's half-sister who died. None of these theories have been confirmed yet by EA. Further clues may come in a later expansion pack, but until then her identity remains a mystery.

Trivia

 * Her name is most likely a reference to the promiscuous young girl in the novel Lolita. Based on her traits (Bookworm, Childishness, Great Kisser,Charismatic), this theory seems even more likely.
 * This could also be a reference to the Japanese fashion style "Gothic Lolita" this can be assumed because the name contains both her for first and last named are contained in the name.
 * The name Lolita is a diminutive form of the Spanish name Dolores.