I rattled myself about it, too. The instant I hit the 'Send' button I realized that it would be impossible for someone born in 1850 to have died in 1848. There had to be another child of the same name. Please forgive my carelessness.
Johanna M's brother Abraham did indeed travel to the US! On the second page of the Apeldoorn marriage record you will see a note that mentions 2 daughters, Margaretha Johana and Hermina Ida Maria, who were born in Liberty, Missouri, Noord America. Margaretha was born in August 1874 and Hermina in September 1876. Missouri records show that Abraham and Maria Kroon were married in Clay County, Missouri, on May 13, 1873. https://dcms.lds.org/delivery/DeliveryManagerServlet?dps_pid...
Obviously, he returned to the Netherlands and stayed for several years. I haven't seen any sign of his return to the States.
The Dutch databases I've been working with are those in FamilySearch, Ancestry.com and the WieWasWie website. I stumbled upon them while doing a blanket search for 'Van Greuningen'.
Liberty, Missouri, is near Kansas City, one of the major hubs for people emigrating West. It is 296 km from there to Holland, Nebraska. About a week's walk, not impossible. A Dutch settlement was started there around 1867.