Is this what we are talking about, when we talk about brides wearing white (and veils): an 18th century interpretation of an Ancient Roman virginal house girl?
“It was not uncommon to depict portrait sitters in the guise of a vestal virgin: many young women were shown in this guise when they were about to marry. The vestals were Roman guardians of the hearth and house who were chosen for their youth and purity; hence the presence of what might have been a table but is instead a brazier. The gold-trimmed robe is not contemporary dress but a costume, and the way in which the young woman lifts the veil is quite typical for the subject.”
Portrait of a Young Woman as a Vestal Virgin, François Hubert Drouais, 1767
The Metropolitan Museum of Art