There’s no need to go deeper. What she offered was the textbook example of heresay. What’s worse is her heresay is actually perjury… since the folks she’s quoting have said she’s lying.
You are right. Hearsay testimony can be false, and therefore grounds for a perjury charge.
In this particular case if her testimony were true it would indicate criminal conduct by the Secret Service agents involved. Refusing to take the President to his desired destination, and then effectively detaining him to prevent him from performing his duties, as he sees them, is highly improper and illegal activity.
A good way to understand the nature of the charges would be to consider what charges the DOJ would bring against a random American who somehow got in the drivers seat of the presidential limousine and took the President, against his wishes, to a location the driver chose when the President was trying to get to the White House, or the Pentagon, or the Congress. It would not be a misdemeanor.