NameValentine Keim 
Spouses
Marriage11 December 1811, Easton, PA
Parent-Proof notes for Maria (Spouse 1)
It is just a guess that Henry had a daughter named Maria, I have no real evidence of that.
It is just a guess that the Maria Mertz who married Valentine Keim was Maria, daughter of Henry.
To understand my logic though in proprosing these relationships, please read my write-up under the heading “Known Daughters” on first the profile of Henry Mertz (Y1) and then his father Jost Mertz (Y).