When Gina's discovered, Cain learns she made a terrible mistake by trusting someone (and she never will again), she was too much sentimental when the situation was asking for rude ways (which she'll start using from that moment: just remember the brutal interrogation method she allows) and she spent too much time thinking about her private life and playing happy when she didn't have the luxury to have a life. I'm sure that's close enough to her thoughts.

Gina made her the way she is when we meet her: lives don't matter anymore (even less than when she shot Belzen), you have to make clear your point to everyone on the fleet (chief and Helo), get what you need no matter what (Scylla), words aren't useful anymore.

I would like to know what you think about the whole issue but I'm more interested in the following: did she know what was being done to Gina, with details? Which were her feelings about it? I'd think she felt sorry in a human way (the part of her that was still seeing Gina as human) but was also sure that was the right thing to do (not bending to make the enemy more comfortable, getting what they needed out of her -no matter how-, winning the war) and, maybe, even believed she really didn't feel -was a machine- or her feelings didn't matter -she was just a computer program.