I mean, another solution is to give warning at regular intervals beforehand (day, hour, ten minutes, 1 minute perhaps). Basically planned outages with ample warning. Of course, avoiding prime time planned outages is always good in any scenario and I'm sure goes a long way to keep all clients happy.
With that said, I doubt your 13 year old daughter client is actually paying for that level of service, so... ;-)
I believe the SLA for a 13 year old is 110% uptime, with consequences being The end of the world.
I am not a lawyer so feel free to go to court claiming that 100% uptime is the limits of mathematics or that the world will not end if <insert social media platform of choice> is not accessible for 5 minutes on a tuesday afternoon. Its a losing case every time, best just to settle up the case quietly with an extra scoop of icecream or some robux and cut your losses.
With that said, I doubt your 13 year old daughter client is actually paying for that level of service, so... ;-)