Hello 2factorIsSoBroke,
Thank you for reaching out in Apple Support Communities. We recommend to delete the Clock app and redownload it from the App Store prior to performing an invasive step such as restoring the entire device. This may help resolve your mother in law's issue with the alarms.
Here's how to properly delete an app:
How to delete an app
1. Touch and hold the app.
2. Tap Remove App
.

3. Tap Delete App, then tap Delete to confirm.
Keep in mind that some built-in Apple apps can't be deleted from your device, so you might not see the option to delete an app. Here’s a list of built-in Apple apps you can delete from your device. If you can't delete an app that's not made by Apple, disable parental controls, then try deleting the app again.
If you touch and hold an app from the Home Screen and the apps start to jiggle:
1. Tap the Remove icon
in the upper-left corner of the app.

2. Tap Delete App, then tap Delete to confirm.
3. Tap Done.
These steps are outlined here: Delete apps on your iPhone, iPad, and iPod touch - Apple Support
From here, you'll want to open the App Store on the iPhone and redownload the Clock app.
Best regards.