This is a very important fact in recovery. Don't blame her or agree if she blames herself. Even if she made some bad decisions, no one asks to be raped. This is the same as with all other reported crimes. Know it was not her fault.
Most rape victims feel guilty and feel that the attack was somehow their fault.
Take control of her life. When a person is raped, she may feel completely out of control of what is happening to her. A significant step on the road to recovery is to regain a sense of control in little, as well as big, things. Give her choices to make and empower her. It is not your place to play prosecutor and make her prove her story.