How narrow can you make firewall blocks? Like, can I block specific YouTube channels? And would there be an alert or something to say it had happened?

I don& #39;t object to my mother having politics that don& #39;t match mine, but she& #39;s moved from news sources to hate sources, and they& #39;re telling her that COVID-19 is not a threat.

I don& #39;t want to fight, but she& #39;s glued to her phone whenever she& #39;s awake, watching extreme hate streams.