Person You Know Who Threatens the Notion of Immigrants and Natives

Although Prensky defines digital immigrants and natives clearly, categorising people into these definitions is not so easy. Prensky does not take any other factors into consideration i.e what about 'digital immigrants' who work in the technology or computer industry, and therefore may have more digital knowledge than a digital native might have.
Personally, the person I know who most threatens Prensky's notion of 'digital immigrants' and 'digital natives' is my Grandma. She easily and happily uses text messages, uploads holiday photos to a computer, and can e-mail. She taught herself most of this, by reading the manual and using previous knowledge.
She often text messages telling me what she's upto and asking how I am, yet she will still write letters and postcards.