I was under the impression that geiko did not wear okobo. In the recent image of Kotoha's erikae, she's wearing okobo...?? Was I wrong? Thanks D:

You’re right - okobo are worn only by maiko (and minarai). Kotoha’s wearing wooden geta in the picture. :) (I think those are called komachi geta but I’m not sure).

Besides okobo for  maiko and geta for geiko,they can both wear zori (in case it’s snowing or raining you can often see them in zori with plastic covers to keep the tabi socks dry).