A Varvæng (essentially, a type of small fairy) with bird-like wings and butterfly-like antennae, Sif looks a a very voluptuous young woman. Her hair is done in double buns with accessories covering them. She wears a dress that looks like a robe gripped on the sides by laces that leaves her legs free on the sides and with a prominent cleavage in the middle of the bosom. Her pupils look like stars.
Silf is only shown teaching Naoya. In this interaction, she appears to be a very competent teacher with a bright personality.
When Naoya is accepted in the women's facilities of the Royal College of Ygvarland as a special exception, thanks to Judit intercession, Silf, the social studies teacher, is assigned as his personal teacher. Silf focuses on teaching Naoya the history of Álfheimr, her specialty.