So why is it HER problem? She should call IT. And management should fire IT for incompetence as they obviously didn't secure the network properly.

If she was a self employed person or a business owner then there's no reason you could not get access to the computer. So I assume she is a wage earner.

Maybe she was afraid of being fired but if her boss would fire her for something which is not her fault (as on a properly secured computer she shouldn't be able to install any software without admin privileges) he is a lousy boss and she could probably sue for wrongful termination.

Unless she is the responsible IT person for the company then she deserves to get fired anyways for not doing her job properly.