Una Meredith is the daughter of Rev John Knox Meredith and sister of Jerry, Faith and Carl.  She has long black hair, dark blue eyes with an aura of sadness about them, and a mouth which occasionally falls open to reveal small, square white teeth. Occasionally, a shy smile creeps over her face. She is the only Manse child who attempts to keep the Glen St Mary Manse tidy, and seems to care more about what others think of their way of living more than her siblings.  She is also the most caring and thoughtful of the Manse children - she was the one to care for Mary Vance when they rescued her from the barn.

Una misses her mother more than her siblings do, and seems to be sensitive about death. Una is thought to have a carefully hidden fancy for Walter Blythe and this is reinforced in Rilla of Ingleside. Rilla Blythe seems to be the only one to have noticed this, as she ends up giving Walter's last letter to Una. At the end of Rilla of Ingleside, it says vaguely that Una intends to take a course on Household Sciences at Redmond, most likely to get over the great dissappointment in love that she has experienced.