I have no reason to doubt her. The SS isn't denying it so it's not even a matter of he said / she said.
Absence of evidence isn't evidence of absence...
They aren't denying it? Where in the article does it indicate that the Secret Service was contacted? There isn't one reference to anything at all from the Secret Service in the entire article. You appear to be a great critical thinker (/sarcasm)
The SS isn't saying anything about one way or another because it isn't our business. It is a matter of "he said/she said" and you take the side of a kid that thought it was okay to banter about killing the President. This speaks volumes about who you are.