Bonnie, I am a Swarr, born in Lancaster Co., Pa., and I have been researching the Swarr line for several years. I have pretty much the same info on the Shirks that you have. Ulrich II married Anna Swarr, his brother Michael Shirk married Anna's sister Elizabeth Swarr, and his brother Peter Shirk married Anna's sister Maria Swarr. Their other brother Casper Shirk and his wife Magdalena Newcomer had a daughter named Veronica Shirk, who married the youngest Swarr brother, my 5G grandfather John Swarr. I'd say there probably weren't too many other families living in their area at the time, since these two families intermarried so often!