Both of Sarah Michelle Gellar‘s characters in RINGER have names rooted in Gaelic. In Ireland, the name Siobham is far more common than is Bridget. (The name Siobhan ranks #77 among female names in Ireland, as common as the name Jane in the United States. Bridget is the 174th most common female appellation in Ireland, as common as the name Yvonne is in America.)
Both names are variants of Joan, and mean, vaguely, “God is good”.