I was referring to MARIE'S parents or siblings not caring about changing her religion for a throne. Of course, her nephew (who was 4 years old when she married the Tsar) wouldn't have any say in the matter. Have you ever read anything from Marie's family stating their feelings one way or the other on the matter? And I was not putting forth a "throne theory"--it was just part of a line of inquery with the hope that some of our posters would have read something on the issue. I don't know one way or the other to form a theory about what the reaction of earlier Hesses might have had towards any religious conversion. Therefore, it is incorrect to automatically surmise that the wasn't consternation towards Marie's marriage unless something has been read of it. Of course, they may have been thrilled. That was my point.
Also, it would have been an accepted part of the deal for Marie's conversion--the Empress had to be Orthodox. Ella, like Miechen and Mavra, was married understanding they didn't need to convert and Ella maintained her Lutheranism for roughly 4 years afterwards. Perhaps Louis wouldn't have acquiesced to the wedding had he known that would happen. Again, I've only read of his post-conversion reactions. For many back then, a potential change in religion was a deal breaker in many royal marriage unless (and, again, not saying this was/wasn't the case with Marie) ambition over-road those concerns. Often, even then, compromises had to be struck.