I used the shortcuts app to crate an automation that would undo all of the things my dad did by accident. Turn of airplane mode odd, wi-fi back on, DND off, turn up volume (unfortunately you can only do media volume, not ringer,) turn up brightness, etc. He tended to over enlarge text so it would reset that. I set it to run twice a day and when he commented the charger. As for the silent switch go into her contacts and find your contact. Edit your contact ringtone and text tone (both) and toggle on "emergency bypass." Now no matter what she does to her phone, you can call her and it will ring.

Another thing you can do is set a schedule for DND to turn on and off for 1 min at different times of day and that might leave it toggled off. I'm not sure if it will just return to previous setting, though.

Here's an example of what I did on his phone. https://www.icloud.com/shortcuts/bd2142db442045308031bbf03f311690

And he would mess up his phone with accessibility settings so I would run this once a day on automation. https://www.icloud.com/shortcuts/f6d5ff3d039841b2b394cea7acd1268e