No you aren't obligated to give her a platform. But if you go stage a protest so unruly that you block her from speaking at a College Campus for instance you have effectively negated her right to free speech. Are you really so infantile that hearing her words will ruin your life? Are they really so dangerous that you can't engage in a debate instead? I am a staunch liberal and the arguments about this coming from the left are truly mind boggling and very troublesome.