Also worth noting… even if we knew for a fact she had no serious intend to carry out her threat - like if there was a recording before and after she hung up the phone laughing about this “prank” - threats on the lives of government officials are crimes. It can influence their behavior. There is no situation where it’s not serious, just like standing up on a plane and yelling “I have a bomb!” is a crime and serious whether a joke or not.