[She smiles slightly.]

Then perhaps you do not have to fight her at all. Not in truth. She has bested you once, but you are not dead. Could she not mentor you? Adult trolls teach the younger trolls in the ways of fighting, do they not? She could be your teacher, and help you to become even stronger than you are now.

[Assuming, of course, this woman wasn't insane and wouldn't just attack Vriska again on sight.]