
Well, maybe a mistake was made.
What about the other children? The oldest was Petertje, born 11 May 1849.

Hmm, right date and name, same other woman for the mother.

Kornelia, born 3 November 1851. Same story. Aaltje was next, born 1854.

Jan was the next child after Aaltje, born 2 September 1857 according to the church, and his birth registration -- and also the child of Lubbertje Hop.

And the youngest was Willempje, born 18 December 1860.
Not likely that an error was made in recording the name of the mother 5 times!! Not likely that there are 2 Willems each having five children of the exact birthdates and names! No, clearly the mother of the children of Willem Morren was Lubbertje Hop. So who is Neeltje Dekker, named in the North Holland (Michigan) Reformed Church register and buried beside Willem Morren in North Holland Cemetery???
A new puzzle to solve.