It could well be a misreading - obviously for the censuses pre-1911 the household returns don’t survive so we will never know what sort of handwriting, inkblots etc the enumerator had to contend with.
However it is also possible that Charlotte and Caroline were treated as interchangeable, being etymologically linked (both feminine versions of Charles). I am not sure whether I have seen an example of this particular one, but it’s a common enough phenomenon with other groups of names, e.g.:
Ellen, Helen, Helena, Eleanor
Emma, Emily, Emmeline
Mary Ann, Marian(ne)
Isabel, Elizabeth