You get her by getting Handgonners in your Party. They're an Alliance of Paneria elite unit. They need to be in your group for 60 days straight with no period of you having none of them. So try to protect them, or make sure to get a large group of them.
bersrerk one question ?? you can train these units to companion status right ?? when you recruit them into become vassal can you train another one into becoming a companion ?? or can you only train one of these in game ??
There are ten. Sometimes one of the mercenary officers you already hired will show up in a bar(this is because I added mercenary officers to the mercenary part of the troops file which adds them into taverns randomly.) But if that happens he will simply say that he is just getting a drink. You won't be able to hire the same one twice.