What causes Rae's loneliness and feelings of abandonment in the novel, Odd One Out?

Rae's father, Dr. Chin, is often busy at the hospital, and he often goes away for conferences, leaving Rae alone, and as a resuly of his absences, Rae often feels lonely and abandoned. When Rae’s parents divorced, her mother left all of them, and her sister eventually decided to leave to live with her Mom. Though Rae loves her Dad, she felt abandoned by her Mom, and her sister leaving suddenly without explanation. Rae feels that her sister abandoned them, and left her when she needed a sister.