Based on the name Guth and the church, the likelhood is that she was a descendant of Peter Troxell, the immigrant in 1733, and likely his son Peter, Jr.
I checked Roberts History of Lehigh County and Troxell Trails, and came up blank but you may want to double check.There were many Guth and Troxell marriages in this family.
Also note that Peter and most of his sons left that area around 1758, and while his son David remained a little longer he moved south around 1775.So Son Peter Jr. Is the likely focal point of research.
Note further though that cousin Nicholas, son of Johannes the immigrant also stayed in this area.
I would start with Roberts vol. III at pp. 1321 which has a Troxell Family history.