All of these are really good examples of writing a good email, except the bottom left one.
The "wrong" example is perfectly fine, and the "correct" example is pretty rude unless you're a project manager addressing your team. Even if you were a project manager, it's still pretty rude.
You can make "brand accounts" on YouTube that are a completely different profile from the default account. She probably won't notice if you make one and switch her to it.
You'll probably want to spend some time using it for yourself secretly to curate the kind of non-radical content she'll want to see, and also set an identical profile picture on it so she doesn't notice. I would spend at least a week "breaking it in."
But once you've done that, you can probably switch to the brand account without logging her out of her Google account.