Your e-mail was passed to me by our secretary Elizabeth Angus. I have checked our two data bases, Shetland Surnames and the Shetland Directory. There are no families in Shetland as far as I can tell with the name German or Jarman. The nearest name is Jarmson or Jeromson which are both patronymic names from the first name Jerome or Jarm.
Yours sincerely, Merryn Henderson. Research Secretary