Why does Abigail move all the way to California in Lovely Bones?

The answer to this question can be found in the chapter
entitled "Snapshots." Up until this stage, Abigail is a woman who is presented as being
haunted by her dead daughter and increasingly alienated by her husband's inability to
let Susie go. She needs an escape from this claustraphobic situation, and so first tries
adultery with Len. However, it is clear that this is not enough of an escape for her.
Note how the idea of going to California came about, and why it was so attractive for
Abigail:

My
mother made it through only one winter in New Hampshire before she got the idea of
driving all the way to California. It was something she had always thought she would do
but had never done. A man she met in New Hampshire had told her about the work to be had
in wineries in the valleys above San Fransisco. It was easy to get, it was physical, and
it could be, if you wanted it to be, very anonymous. All three sounded good to
her.

Thus we can see that
Abigail went to California because it was something that she had always thought about
doing before the onset of family life. In addition, she could easily pick up physical
work, to help her forget her worries, and she could remain anonymous, and avoid the kind
of questions that would prevent her from truly escaping.