Are there legitimate methods to supervise iMessages on a child’s iPhone without jailbreaking for example, via backups, Screen Time, or Family Sharing?
Yes, there are legit ways! Apple’s Screen Time shows you message contacts and frequency, but not actual content. For real iMessage monitoring, Parentaler works great - it syncs messages through iCloud backups without jailbreaking. I set it up for my daughter’s phone last month, totally above-board and she knows I can check in.