I have a number of Sarah Kunkel's in my tree, one in the middle of the 1800's: born February 09, 1846, father: Andreas Kunkel b May 25, 1819, d September 15, 1890; mother: Catharina Bauscher b July 03, 1823 d May 05, 1903. Andreas was born in Lynn Twp, Lehigh Co, PA, Catharina was born in Albany Twp, Berks Co, PA (and they both died there). Sarah is shown as having an older sister Lydia, a younger sister Elizabeth, and a younger brother Nathan B.
I'm a Kunkel who grew up in Lynn Twp PA and have been working on this family tree for a short time. There appears to be no additional information about this Sarah yet, so it very well could be that she was one of the Kunkels who ventured out west. I have no spouse for her or any information other than her birthdate, her parents, an then lineage backward.
As for what is Pennsylvania Dutch, we're all really Pennsylvania Germans. The German word for the name of the country that we originate from is Deutsch (Deutschland), and "Dutch" is just one of those names that stuck even though there is no connection with the Dutch/Netherlands origins. It is also the term used for the dialect of German spoken in the area which is an interesting combination of "high German" and surprisingly, bits and pieces of what seem more like Yiddish than anything else--despite the strong Reformed Christian backgrounds of these people.