Anne Blythe, called Nan, is the eldest of the Ingleside twins--the other being her sister Di--and is the third child and first daughter of Anne and Gilbert Blythe. She is "Blythe by name and blithe by nature" as one of her teachers once said, being a dainty little maiden with velvety nut-brown eyes and silky nut-brown hair. Her complexion is almost flawless, and she is well aware of this. She has many friends, but is thought to be stuck up and proud by the Glen St. Mary ladies, especially "Kitty Alec" Davis, because she imitates her mother's tricks, graces and poses. Nan also inherited her mother's imagination, which makes life more interesting, and also gets her into numerous scrapes. Nan is named after her mother.

The third Anne book she appears in, Rilla of Ingleside, shows the eldest of the Manse children, Jerry, making "sheep's eyes" at her. It seems Nan loves him too, as when her brother Jem announces that Jerry will want to enlist to go and fight in the Great War, she says a sharp "Oh!" and runs from the room. Supposedly, they will have married after the end of Rilla.