Surname Saturday - Konings - Brick Wall

My ancestors Dirck Smetsing and Sophia Katarina Konings were married on 15 August 1721 in Lobith. Lobith is a village at the border of The Netherlands and Germany. Deck lived there, and had become a member of the church community of Lobith in 1716.
“Düffelwarth” was where the bride, Sophia Katarina, came from. Düffelward is located on the former Roman Road between Xanten and Nijmegen, just across the border near Cleves.

David Smeltsing and Sophia Katarina Konings were married on 15 August 1721 in Lobith

Derk and Sophia Katarina had 6 children baptised in nearby Doesburg:

1. Johanna Smeltzing was baptised on 1-11-1726 in Doesburg. Her burial was registered in Doesburg on 1-3-1784. Johanna married there on 7-5-1754 Isebrandt Heemskerk. They had 10 children.
2. Johannes Sigismond Christoffel Smeltzing was baptised on 21-4-1728 in Doesburg.
3. Louisa Smeltzing was baptised on 3-5-1730 in Doesburg. Her death was registered in Dordrecht on 28-1-1811. Louisa had an extramarital relationship with Johannes van Hessels that resulted in a daughter Johanna Maria Smetzing who lived for only a few months in 1755 in Doesburg. Louisa married in Dordrecht on 18-5-1760 David de Sterke. He was baptised on 6-2-1733 in Dordrecht as son of Pieter de Sterke and Lijsje Kevers. David died from a lung disease, and his burial was registered on 14-12-1797 in Dordrecht. They had 6 children, including my ancestor Pieter de Sterke, the father of Arie de Sterke (1796-1892).
4. Anna Maria Smeltzing was baptised on 13-2-1732 in Doesburg.
5. 
   Sophia Smeltzing was baptised on 11-12-1733 in Doesburg.
6. Henrik Adriaen Smeltzing was baptised on 20-4-1736 in Doesburg.

I haven't been able to find the parents of either Derk Smeltzing or Sophia Katarina Konings.

Sources: RegionaalArchiefDordrecht.nl, nl.Wikiepedia.org.