Yes, the Name-Marr tag type could easily be used with a 1901 date, a note in the memo, and cite the 1901 census as the source.
If the tag is left as a non-Primary name tag, then it can produce a sentence in your narratives if you include this tag type. As its default sentence includes the date variable and the memo variable, you can explain this situation in this tag memo. That should explain the situation to anyone reading your narrative reports.
However, I prefer to generally not include any Name-Marr tag types in my narratives but still define them for the sake of indexes. For that reason I have added some custom Name tag types to use when I want to describe something unusual for a person. One example is my very general purpose Name tag called Name-Comm, where I can include whatever I want about the situation in the memo, such as a date. See the description of that custom tag type in my book here, and it sentence here.
Hope this gives you ideas,