You’ve turned on iCloud backup for her now, right ?
She has a 64gb phone with about 7 million photos on it, almost full.
I need to back it up for her regularly
200GB of iCloud storage is $36/year.
100GB of Google Drive storage is $20/year.
I like Google Photos for any smartphone user. It makes storage management a breeze by deleting all backed-up photos from the phone, but in the Google Photos app there's no visible difference between the photos in the cloud and on the phone (as long as you have a signal).