Yes, they are valkyries; pictured here, clockwise from bottom: Lenneth, Ahly, and Silmeria; but in the mythos of the game they form a triumvirate of goddesses who personify the past, present and future.

Not unlike what the goddesses Urd, Skuld, and Belldandy (Bellandy in Norse myth) symbolise.

Scanned from the Valkyrie Complete artbook that came with the Silmeria Artifact Box.