Sadly, the main things I learned about missing persons having researched a lot for my novel is that if they don't come back of their own volition, very little is done officially to find them. The police care very little about cases like that, and there isn't much that people can do other than make a fuss themselves, rally people into search groups, spread the word. Generally, most missing person cases are fully resolved within one year; as a statistic, that's not exactly a great amount of help to those close to the missing party. Luckily, she's a young white girl, the media loves a missing young white girl, so she's got more going for her than most other missing persons.