NIIRC, Nana Visitor played Major Kira, not Ensign Ro.
Correct. Ensign Ro was played by Michelle Forbes, whose most notable roles, at least to me, are Maryann Forester on True Blood and Admiral Helena Cain on Battlestar Galactica.
Apparently she has been in a shit-ton of stuff. Maybe turning down DS9 was a good choice for her. Nana Visitor seems to have had bit roles since her DS9 run except for some show called Wildfire, and she was on Dark Angel, but nobody noticed because Jessica Alba's lips at that time took up the entire screen.