Strong support.  If anything one can make the point that Mary Miller (actress) is the primary use.  Just because some one writes books and they are used as sources in articles is not a good way to determine primary use.  I'd argue that the 59 references used to write the Mary Miller (actress) implies a much more notable person and better makes the case then another article that is based on only a single reference.  I think that adding Mary Millar in the list of statistics confuses many since it is just a similar spelling and that would be better handled as a See also on the dab page.  Obviously this means that the current page needs to be disambiguated to Mary Miller (art historian) to allow the dab page to be moved.  Using the statistics provided in opposition to this proposal clearly shows that, if anything, the current article does not even receive a majority of the hits.  So while that is not a good way of proving primary use, in this case it makes a strong case that there is no obvious primary use so the dab page should be moved. Looking at the numbers in a less biased way you see:
 Mary Miller (disambiguation) 0 (newly created)
 Mary Miller (actress) 275
 Mary Miller 679
 Mary Millicent Miller 567 (newly created)
 Mary Miller Glasscock 32 (newly created)