HI Hermia,
Currently you will need to install 3rd party content filtering software directly as part of the images on the student VMs. Also, you may want to have your student run as a non-admin user so that they can't uninstall or modify the content filtering software.
If you're interested in trying this approach, please message me directly. It would be great if we could schedule a short phone call so that we can discuss more details of this option.
Thanks,
Nicole
