NameEsther Fisher 
Spouses
Birth24 December 1817
Memo(find-a-grave)
Death15 October 1880
Memo(find-a-grave)
BurialBlue Church, Ralpho Twp, North'd Co, PA
Birth, Parent-Proof, Designation notes for Charles F (Spouse 1)
All sources that cover the early Northumberland County Martzes say David and Magdalena had a son Charles. Meiser identifies him as Charles F Martz (1817-1880) and says he married first Elizabeth Haas and “apparently” second Esther Fisher.
That Charles F is buried at Blue Church where his brother David is buried. The dates match and from his find-a-grave memorial, the names of his wives match. I have found him. He is designated P6a5.
Death and Find-a-Grave notes for Charles F (Spouse 1)
Charles and his two wives are on find-a-grave.