Well there is a big distinction between killing in the line of duty and being a killer. However I don't think that is what you were trying to say, it seems like your only issue is if she enjoys doing those things, and that's something one you can know. Maybe you should bring it up someway in conversation, maybe like do you ever think of the things you had to do in your job? Do you ever regret anything? And see where the Convo goes from there, if you know her well you can read how she responds.
As far as torture goes it honestly seems disturbing and counter productive for the most part, there may be instances where it worked but think of all the people who were tortured who may have simply not known anything, but that's a separate issue of course.