Bella Goth

Bella Goth was one of the pre-made Sims shipped with the original "The Sims" game, in which she lived with her husband Mortimer and her daughter Cassandra. In The Sims 2, Bella no longer actually exists (as in, the bella married to Mortimire, cheated with Don and parent of Cassandra doesn't technically exist, from a program point of view); however, her essence lives on in two ways.

Bella's disappearence from the game is a major component to the background story of Pleasentview, the neighborhood where her family lives. The story does not explicitly state what happened to Bella, although her husband and children and Don Lothario have memories of her being abducted by aliens. Many of Mortimer's memories involve Bella, as do Cassandra and Alexander's. On the family tree panel, Bella's face isn't greyed out. This indicates that the game considers her not to be dead.

Although the actual Bella is gone, Maxis created a likeness of Bella and used it as a townie in another neighborhood, Strangetown. This version is a little different than the actual Pleasantview Bella Goth, but is acknowledged by Maxis as the same Bella. The only was of sending Bella to Strangetown (without messing up the game code) was to create an new Bella! So that's what they did! And they say the reason she cant remember anything is because she got abducted and got tested with.

Mucking about with the programming
Is generally not advised. Even moving Bella out of strangetown causes the equivalent of a migraine to a computer. Nothing good happens either- no tearful re-union, she is not acknowledged as Cassandra's mother nor Mortimer's husband.