If she is descended from a child of Benjamin Harrington and Elizabeth White, then the origin of the family is in England. Benjamin could not read or write and signed an X next to his name, as written down by others. Hence the mispellings of Herrington,Herendeen, Hearnden and Herndon.His offspring each went by different spellings, though it did revert to Harrington for the vast majority of them. He entered North America at Boston, Mass. around 1630. His mother stayed in Cambridge,Mass and a brother, Robert Harrington, in Watertown,Mass.
Double check for your Sarah's parents names. I'll be glad to help if you send me exact bdates, death dates etc..