Recover photos from iCloud backup.
My parents and I just returned from a trip overseas. While there my mom and I got SIM cards for our iPhone 5s so we could use them. The people at the store we got the SIMs at made some changes to the settings and said that when we got back and put the original SIMs in the settings would return to their previous state. They didn't. When we got home Mom (or Dad, it's not clear who) got the bright idea of restoring Mom's phone to a backup from before we left. That put the settings right, but several hundred photos are gone. They had restored it before she imported her photos. So now she needs to get them back. She said it is backed up to iCloud, and her most recent backup before we got home should have all of her photos, right?
I just want to make sure before I do anything that the last backup will have them all and I don't need to do it in steps.
iPhone 5, iOS 8.3