Why did her birthplace on the passenger record show as Casin which I believe is in today's Bosnia -- back then, it would have been part of the Austro-Hungarian empire as well. I would try getting in touch with Johann Meyer at the link I sent you -- he may be able to help you find their marriage record.
http://www.dvhh.org/banat_villages/Timis/Busiasch.htmThey have reunions of village members regularly in Germany -- with the latest just being this year.