"It started off quite ordinary," defence counsel Noel Rayner said.
"She was expressing her frustration and that escalated."
About halfway through the six-minute conversation, Holkenbrink became overwhelmed by her rage.
She told the call-taker she was going to stab the property manager, punch her in the throat and "blow up" MSD offices.
The building went into lockdown for a day as a result.
The defendant's words were passed on to the victim who became "terrified" by the possibility of retribution.
The court heard the woman feared Holkenbrink would come after her and engaged security to escort her to and from work.
Rayner accepted the offending was aggravated by the fact a public servant was the target of his client's wrath.
However, he pointed to a "very articulate" letter of remorse written by Holkenbrink which recognised the wide-reaching consequences of her conduct.
Judge Michael Crosbie highlighted the fact the defendant had significant personal issues that served as a trigger for the offending.
Holkenbrink was sentenced to four months' community detention and 15 months' intensive supervision.