I've maintained my iPhone's battery health at 100%, even with daily use.
Here are the ONLY 10 tips for preserving your iPhone’s battery health that actually work (and I personally use them) 👇🏼
If you go through her phone, don’t go through the usual stuff. Go through her recent location on an iPhone by going to settings, privacy & security, location services, system services & then significant locations. There you can see every address she’s been, dates & time.