Maria had better not be too picky about a wife to the point where she ends up ruining his life. If she wants a princess, there are plenty out there who have careers and there are more dethroned than enthroned royal families out there and while a reigning family might be preferable, a dethroned one could be just as grand. You can always make money, but ancestry is something else entirely.
Too many mothers (or men in general) have suc ha huge list, that they are unwilling to sacrifice or work on the one small thing that the potential spouse falls short on. You can always make money, you can always work on etiquette, but Maria needs to focus on finding a wife that won't make a mess of Georgi's life. She should find someone who is pliable, agreeable, with a strong moral foundation and also make sure that Georgi appreciates his new wife as well.