How can she be pardoned when she isn't even indicted for anything yet?
Barry doesn't have any way to give her a "Get Out of Jail Free" card she can use whenever she's finally indicted or convicted, he can only pardon her if she's convicted of being guilty of something.
Is Lynch going to indict her so Barry can pardon her or what?
Not the case - Ford pardoned Nixon and he was never charged with anything.