You can notify the police on her behalf: anyone aware of a crime, not just the victim, can report it, and if the authorties deem it serious enough, they may file charges regardless of what your daughter wants. You can't, however, force them to file charges--the authorites (e.g. prosecutor) decide whether to do that; and because your daughter is now an adult, you cannot sue him on her behalf--one adult may not sue on behalf of another competent adult.