Hi Friendlygrandma,
welcome to the Apple user-to-user Community.
Re: iPad got put to black
Wondering, like you, how to fix the problem ... am no expert on this ... can only offer a few suggestions
Eg: If Siri settings are in place: try asking Siri to turn up the brightness
Try asking in a couple of different ways if necessary eg: "Hey Siri, turn up the screen brightness" or "Hey Siri, brighten the screen" or "Hey Siri, Set the screen brightness to Automatic"
Siri info, if needed:
Use Siri on iPad - Apple Support ... or Use accessibility features with Siri on iPad - Apple Support
If you gain access to the iPad... here are different ways that you can make changes:
See how to: Adjust the screen brightness and color on iPad - Apple Support
How to: Restart your iPad - Apple Support
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If all else fails
You may be able to connect the iPad to a computer.
This may allow you to try to access it's settings, or, if needed: you could erase the iPad.
NB: If you don't have a back-up, you would lose all your data if you erase the iPad.
Then set it up again, like new, or with a back-up installed.
See how to: Erase iPad - Apple Support for how to connect to a computer
All the best :-)