I think your Anna M. born 1834 was our Maria Anna. That she was called later Anna Margaretha doesn't say that we have to different persons. That makes the problem to identify the people much bigger. But we have many cases that people were called with different first names. But on our page you can see a source from our Staatsarchiv that the two Kruse I talked about left Oldenburg in 1853 and that makes me think that we have the right persons. And in that source was sayd that there two persons came from Langförden.
Best regards,
Gunter