Where'd You Go, Bernadette

Where'd You Go, Bernadette by Maria Semple, 330 pages

Told from the perspective of the 15-year-old daughter but consisting mostly of correspondence between various characters, this story focuses on Bernadette Fox and her antisocial behavior, extreme agoraphobia and utter disgust with Seattle, the city she lives in.
The daughter, Bee, has requested a trip to Antarctica as a reward for getting all A's in 8th grade (couldn't figure out the 15-year-old 8th grader part). The idea of planning and taking this trip makes Bernadette panic beyond any panic she's ever felt. To help with the trip planning and life in general, she utilizes a remote assistant named Manjula located in India, who takes care of all her scheduling and purchasing needs.
You slowly learn more about Bernadette and her back story,  and her reasons for her odd behavior.
The turning point in this story is when Bernadette suddenly goes missing without a trace. Bee is determined to find out what's happened to her mother, no matter what it takes.