Technically, Cassandra Cain was never Batwoman, afaik. Wiki says; Batgirl, Black Bat and Orphan.
Technically, the whole Cassandra Cain thing is one of the fairly convoluted arcs out there. It started quite well, ran through the Batman No Man's Land, and the Bruce Wayne in jail for murder thing. Then it started to go a wee bit weird from what I recall.
Batwoman was actually Katherine Kane, and she was a white girl, so fairly different from Cassandra Cain. Some people got confused there on which was which...