In the jewish faith, when a man and a woman are married, they each wear only a single band to symbolize their marriage to one another. it must be an enclosed circle (no beginning and no end). I am jewish and it's been a big thing in my family, as I married a Catholic.
My great grandmother had a very tiny white gold band that was her wedding ring. It's been passed down to the first born daughter and I have it. I wear it on my left hand. When I got married, for the first year, I only wore a wedding band. Now I wear a one piece diamond ring where the engagement ring sits within the band.
maybe she's Jewish?