I don't know the parents of Polly (Mary = Maria) Coltrider (Kaltreider) who married Geroge Petry, but I would point out that George Petry's mother was a Kaltreider. Catarina Kaltreider, d/o Duvald Kaltreider & wife Elizabeth Catherine (surname ?), was born 13 Sep 1752 (where?) and died in York Co., PA, 13 Apr 1815. Her husband, George Petry, Sr, was born 1 aug 1762 in Strassburg, Alsace, and died in York Co., PA 1 Jun 1823. My notes for George Petry, Sr are: "?3 Sons of Steffan Petry?  pp. 9, 25: vital statistics; ?immigrated to America with his father [Steffan Petry], 1764; 124 acres, 2-story brick house; another house, same land, occupied by brother, Henry Petry (I); brother-in-law, Michael Schlothauer, owned 252 adjacent acres; received from father 252 Codorus township acres?; 7 children." I notice, too that a George Kaltreider holds a farm next to Steffan Petry, George and Henry Wehrly, and others in this early period in West Codorus township, York Co., PA. My guess is that Polly Kaltreider is either the d/o of this George Kaltreider, or niece.