An unmarried woman.
The fleece which was brought home by the Anglo-Saxons in summer, was spun into clothing by the female part of each family during the winter. King Edward the Elder commanded his daughters to be instructed in the use of the distaff. Alfred the Great, in his will, calls the female part of his family the spindle side; and it was a regularly received axiom with our frugal forefathers, that no young woman was fit to be a wife till she had spun for herself a set of body, table, and bed linen. Hence the maiden was termed a spinner or spinster, and the married woman a wife or “one who has been a spinner.” (Anglo-Saxon, wif, from the verb wyfan or wefan, to weave.)
The armorial bearings of women are not painted on a shield, like those of men, but on a spindle (called a “lozenge”). Among the Romans the bride carried a distaff, and Homer tells us that Kryseis was to spin and share the king's bed.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894