Welcome to my world! I am always puzzling about how to better gather stats from Wikipedia in order to compare to Commons or other language-pedias. The category system is hopelessly muddled (and sometimes even circular) and doesn't match up across languages. The Dutch Wikipedia looks down on the English categorization system and doesn't like over categorization. They take this so far that they now have thousands of painters in the non-diffusable category "Dutch painters" and are one of the few language-pedias without a category for "Dutch Golden Age painters".
That said, you have hit the nail on the head as far as the mission of Wikidata goes. I have been an enthusiastic contributor there, mostly to the paintings project called "Sum of all Paintings" (SoaP). Thanks to the work of lots of GLAM enthusiasts there who work on artists in various collection databases, slowly artist Wikidata items are being filled with useful data, such as gender, place and date of birth, field of work, occupation, awards, degrees, and so on. We have a ways to go, but thanks to the Wikidata gender game we have lots of gendered data available now. I first started to keep track of this for artist matches to the RKD database, which includes gendered data, as a way to see if Wikipedia was at all on target. I assumed that of the artists in the RKD database Wikidata has the "most famous" and that of these matches, Wikidata would have a higher percentage of women than the RKD percentage, because Wikipedians have been working on gendergap in content for several years now.
It is sort of hard to tell, because Wikidata is still so young, but I have compiled some information here: