Assuming you can print other than when on the internet, I would delete and then re-install the printer as an opening gambit.
You could check the spooler settings, if its not set to "Start Printing Immediately" then set it to see if that works.
It could be a corrupt file withing the browser. What browser is she using? Is it the latest version? Does a different browser work.
Check if the firewall is preventing printing.