I say no pardon. As I understand it, Hillary would then be free to answer any and all questions regarding Obama without fear of self incrimination. She doesn't have to 'plead the 5th' or use the tried and true 'I don't recall' defense. She can sing like a bird regarding Obama with no consequences. A 'tell all' re the Obamas? I think Hillary would relish the thought, as would Bill.
Obama violated Federal Law in not reporting that Hillary had an unsecured server. . and probably many other violations unknown to us but known to insider D.C. attorneys such as Judicial Watch, etc. The probably would love to subpoena Hillary and do depositions regarding potential violations of law by Obama.