I think so. Gerald Ford gave Richard Nixon a general pardon for any and all crimes he “may have committed”. No convictions on the books. I’m guessing something like that would do it. But that carries its own stigma.
That was part of the plea bargain for Nixon stepping down. It was not a regular pardon. Neither was the Marc Rich pardon. Neither followed normal procedures
If Obama were to pardon her he would open himself to being charged himself since he is not without “sin”!