Supernatural maidens (not necessarily young) dressed in barbarian warrior fashion, riding huge horses to take the souls of dead warriors to the big carousing hall in the sky. Valkyries are often mezzo-sopranos. One Valkyrie hit the big time (the analogy is the nurse who ends up married to a consultant) when she became Mrs War, and in good time the mother of Panic, Terror and Clancy. It is unclear as to whether or not Mrs War is still an active Valkyrie, although the presumption is that she helps out at busy times.
Another Valkyrie confronts a very young and nervous Susan Sto Helit when she has to take over from Death due to one of his fancies. On the battlefields of the Hublandish Vasung and Bergund tribes lay a lot of the slain, but the soul of one Volf Volfssonssonssonsson was left tied to his body until Susan worked out where he was and let the Valkyrie cart him off to the fabled Halls of the Slain.
In Wagner's epic The Nibelungs Ring the voices for the nine valkyries are scored as four sopranos, four mezzo-sopranos and one contra-alto (plus a fifth soprano for Sieglinde, stretching any opera ensemble to its limits).
Norse saga does emphasise that Valkyries can have something approaching a "normal" off-duty life which can include marriage and motherhood (reference War's marriage to a Valkyrie). Helgi Hundingsbana was a Valkyrie who took such a shine to one of her post-mortem passengers that she married him. The fact her spouse was technically dead did not prevent resultant children from making an appearance.