There were six Overbeck sisters. Four of them established Overbeck Pottery in their home in Cambridge City, Indiana. They won many awards from 1911 to 1955. (Elizabeth Overbeck made the vase shown above.) Read about the Overbeck sisters HERE on a site dedicated to artists of Wayne County, Indiana. More history HERE.
Follow this link to see Fairies Vase on ebay:
I wrote about the mysterious Cottingley Fairies photographs (1917) HERE