Each State has toll-free hotlines for victims of rape. Nearly every locality across the US offers free, confidential rape counseling. However, as previously pointed out, you cannot do these things for your friend - she has to be willing to take the steps to get help for herself, which might include speaking to her family members, getting in touch with support groups, and contacting a rape crisis unit in her area.
Best of luck to your friend and bless you for your concern for her well being.