Is it customary for women to wear white clothing on Yom Kippur, or is it largely a custom men observe?
I've seen a lot of women do it -- maybe not quite the same percentage as men, but it's not unheard-of.
I don't know of particular standard-identity communal practices, though. (E.g. I don't know what dyed-in-the-wool Chabad women do, nor Satmar or the like.)
The general thing to keep in mind is to be dressed appropriately. (I think some women, in some circumstances, might find white tricky to pull off in an appropriate way, but that's not for me to dictate.)