The spelling of the name "Gerrilyn" is pronounced as /ˈdʒɛrɪlɪn/. The first part of the name is "Ger" with a soft "g" sound, which is pronounced as "j" /dʒ/. The second part of the name is "ri" with a short "i" sound / ɪ/. The final part of the name is "lyn" with a short "y" sound /ɪn/. Therefore, "Gerrilyn" is spelled with two "r"s and one "l" and pronounced with a soft "g" sound in the beginning.
The name "Gerrilyn" does not have a widely accepted etymology as it seems to be a modern invented name. It may potentially be a combination or variation of other popular names such as Geraldine, Gerilyn, or Marilyn, but this is merely speculation. Since there is no definitive historical or linguistic information available about the name, its origin and meaning would likely be best understood in a personal or family context.