hi, when they start escaping, listen to the conversation, there are hints in it where to run ("the right way", "hope elin left" and such)
you need to have solvent and chemical in your bag before the fight start or else she will be stronger. also make sure that you have rations so that your defender can block her strong attack. then use the order lacerate->firearms->regroup->tagteam->trueshot->defend. if you still cant win it means that you didnt finish enough missions in alfheimr and your stats are too low.