The days of multiple family members using the same computer are long gone. Do you ever log into anyone else's desktop/laptop, or does anyone else ever log into yours? That's what I'm getting at.
Yes, actually. My wife occasionally logs into my desktop and vice versa. But I take your point - it's far less common than it used to be, even if it does still happen.
A separate account for kids would make this cleanup unnecessary. They don’t want to screw it up for her, they just do what they think will help with their activities.