I have two Sinnsin my tree who were in the area of Frederick, MD. One, Susanna Sinn, b. 2 May 1735 d/o Henry Sinn & Elizabeth ? She married Johann Caspar Beckenbach.
The other one is Barbara Sinn, d/o Johann Sinn & Anna ??. She married Andrew Michael, Sr. Andrew was a blacksmith in Frederick, MD and a member of the Lutheran church there. The Michaels are connected to the Beckenbachs as well.
I am sure the two Sinn families are connected, just don't know how. I am not a direct descendant, so do not research the Sinn Family name. My connections is through the Beckenbachs. I have nothing else on the Sinns, but will share what I have on the Beckenbach descendants of the two Sinn girls.