Why, what could she have done being what she is? (line 11)
This line seems to give Gonne a break and to suggest that maybe she is not responsible for inciting violence after all. But look closer: he gives her a break because she could not help being who she is...that's like saying to someone in an argument, "Well, I guess you just couldn't help it, because you're such a jerk!"
Was there another Troy for her to burn? (line 12)
The speaker puts Gonne's actions in a historical and metaphorical context, comparing her irresponsibility to the irresponsibility of those whose actions caused the destruction of a great city. That's a pretty heavy burden to lay at her feet.