I smell a Fifth Amendment among other things. This old bag had no business working for the U.S. Government.
What's up with Congress sticking its nose into potentially criminal acts? What legislation does this impact? Hypothetical question, I know the answer. Congressional hearing are conducted for the benefit of individual congressweasels. It's for show.
Let her listen it to Grand Jury first.
She was a perfect fit for the cause.
Tell the truth under oath? Never happen.
I put the odds of her claiming 5th Amendment rights above 90% - IF the hearing is a serious one.