For a story that plays in the 19th century (:
Victoria Choose 50%
Elisabeth Choose 26%
Klara Choose 24%
Comes on the character and history! Victoria looks very nobil and can be found everywhere in Europe. Elisabeth looks very british. Could be both nobil as well as bourgeois. Klara looks more bourgeois and rather in the German-speaking world.
I would say Elisabeth, as the name acts something "older"
I find all 3 nice but Viktoria is best.
I like all three names. All have something special and beautiful.
I find Elisabeth sounds very nice.