Do gifted readers exist?

With math, giftedness is obvious (I think).

Is it the same thing with reading and writing? 

Agatha Mary Clarissa Miller was born, the last of three children, on Sept. 15, 1890, to the former Clarissa Boehmer (known as Clara), who was susceptible to fads and spiritualism, and Frederick Miller, a jolly idler whose death in 1901 left the family in reduced circumstances. This being an era when cutting back, for the middle-class Millers, meant renting out their Torquay house and decamping to Paris and Cairo. Childhood education was sporadic. Clara disapproved of formal schooling and of children learning to read before the age of 8, so her daughter taught herself. “I’m afraid Miss Agatha can read, ma’am,” the nanny announced apologetically when the girl was just 4.

Agatha Christie’ Review: The Queen of the Cozy by Anna Mundow | Wall Street Journal |  3/2/2018