I haven't found any 1910 US census record for anyone whom I think might have been the couple. If they went into show business (vaudeville) they may have taken on stage names and used them for other records (like the census.)
* If they were in the US during the 1910 census, they may have been traveling/touring with some show and missed being recorded for the census.
* They were not in the US at the time of the US census.
Right now, I think the research is at a brick wall. I realize how frustrating that can be.