Had a long-winded comment but it never got posted. whoops. my main suggestions would be Croatian "Darija", Ukrainian "Daryna", or Russian "Dasha" (not slavic, slavic names just sound cool)
Or, if you wanna go super crazy, "Odarka" is somehow related to "Daryna", and Finnish has "Tarja" that's related to all the other names I've listed
Got a spinning wheel when posting that comment. This is a test to see how long that lasts. (update: forever, but it posts instantly)
To make sure that this comment isn't useless: You could always do a diminutive of Darren (i.e. Darrie, Dara*, Darrey, etc.)
*Dara, while fitting the whole feminization thing, is actually a male name from Irish and as such is used as a masculine name in the British Isles, although most cases elsewhere are as a female name