Yeah, none of the main characters use shields, probably because shields and a bashing, brute force aspect to single combat, but regular soldiers probably used them (they don't have the extensive sword training after all).
I may be wrong, but i seem to recall the Children using shields, but my mind may be playing tricks on me. In addition, i assume that the cavalry use shields in general, as two-handed weapons are real awkward on horseback (the whole neck of the horse is somewhat inconvenient).

Clovis