Girl: At first, equipment (Gir or Gear) for going into battle; also, a child of either sex before puberty (Gir + l = little gear), identified by its clothing, not by its identity. Before clothing covered it, this creature was a bairn, a thing born; then it was a piece of gear (all girdled and garlanded); then, after puberty, it gained a third identity, as a woman or a man (again, not an individual identity). The identity came largely from the clothing (a married woman, for instance, is still known by the kerchief, or wipe (wife), women once wore in their hair). Where humans are creatures of the earth, an individual identity is like this: an amulet called a name; it is something you keep. You can do magic with it. You, however, are the earth. The image below shows your author in his girl (gear) days, likely early 1959 but perhaps very late in 1958. You’ll have to figure out which creature below is the one in question, I think, as their outfits are much the same.