I do not understand why she would need immunity from a statement made on an affidavit. Do you?  There is no perjury involved since the statement was to lawyers representing their client and not made to federal officers.  She wanted to be left alone and was ashamed of the publicity. This is common among rape victims.  
 http://www.slate.com/articles/news_and_politics/explainer/1999/03/is_juanita_broaddrick_telling_the_truth.html

Ken Starr was not nominated to the Supreme Court. Many blame the Clinton smears. Accusing Starr of “abusive performance toward women” while excusing Bill Clinton is classic misdirection.  

Jim McDougal penned his tell-all book in Federal Prison on his death bed. It included Bill Clinton’s promise to give Susan McDougal a pardon. Bill Clinton denies the promise but gave Susan a full pardon.   

Yes, Monica Lewinsky was legally an adult but was still victimized by her boss at work. She wasn’t under-age. Those allegations about Bill are another story.