She should be waterboarded.
She's a minor figure in a scandal of immense importance. She's also a US citizen and has every right to seek shelter in the protections offered by Amendment V.
The scandal here is a feckless and incompetent GOP leadership in the House of Representatives, who have failed to conduct a proper investigation of this matter, and who, to cover up their failure, keep pointing at Lois Lerner (whose testimony they could have procured via immunity in five seconds, two years ago), saying, in effect, "Look! A squirrel!"
Look back to 1973. Richard Nixon had been re-elected with 520 electoral votes and 60.7% of the popular vote. If any opposition party in Congress should have feared investigating a President for high crimes and misdemeanors, it was the Democrats in 1973.
But Mike Mansfield and Carl Albert knew what they were doing. They appointed special investigative committees, and charged each with exercising their constitutional responsibilities. They chose the public face of those committees with care (Sam Ervin and Peter Rodino). They hired staff who were passionate about bringing Nixon down, and gave them free reign. They chose their witnesses with care, and brought them before the public in a specific sequence designed to heighten the drama as they built their case.
All this to get even with the largest electoral vote winner IN HISTORY, until Ronald Reagan.
But, of course, they knew what they were doing.