Story ID: A pre-teen girl who is a genius crosses the country in a van

Question

This was a novel I read years ago. I have no idea what the cover art was because the cover was missing. The novel is about a girl who survives World War III. I remember the war was (mostly) biological, and a bacterial strain became nasty when exposed to radiation. One of the details I remember is that she is basically a mutant and immune, like a small portion of other people in the world. She has a genius intellect, is a black belt, and has a blue parrot.

She takes off to search for other survivors in a 4 wheel drive van. The entire story is told as a series of journal entries in a very terse style.

It was a good book, but I can't seem to remember what it was called or who wrote it.

Answer 1

Sounds like Emergence by David Palmer. Also subject of this question, which means it would be a duplicate if you accept this one as valid.

The wiki entry contains most of what you remember, from the biological war:

The following day a worldwide attack, featuring a bionuclear plague, wipes out virtually all of humanity

Preteen girl being a 'mutant':

Candidia Maria Smith-Foster, an eleven-year-old girl, is unaware that she is a Homo post hominem, mankind's next evolutionary step. Hominems have higher IQs, they're stronger, faster, more resistant to illness and trauma, and have quicker reflexes. Their eyesight, hearing, and sense of smell are superior as well.

Has a parrot:

With pet bird Terry, a Hyacinthine macaw, her "lifelong retarded, adopted twin brother," who tends to "parrot" Candy's words even before she speaks, she survives the attack in the shelter beneath their house. Emerging three months later, she learns of her genetic heritage and sets off to search for others of her kind.

Written entirely in super terse style:

The book is a first-person narrative, written in the form of Candy's journal, in what used to be referred to as "telegraphic style", which is based on the means employed by those sending telegrams via Western Union late in the 19th and first half of the 20th centuries to save money. At that time telegrams were the quickest way to transmit hardcopy messages over significant distances. They were expensive; Western Union charged by the word. Hence unnecessary words were omitted: pronouns, conjunctions, most adjectives and/or adverbs.

The primary narrator's voice in Emergence is thus a sort of "verbal shorthand", and she wrote her journal in Pitman shorthand.