See text messages
See child’s texts messages
iPhone 14
Hello S.K.8878,
Apple does not allow you to read any sort or text messages (SMS/MMS), even if the account is designated as a child account. This would be an invasion of privacy. The only possible way to do this would be taking your child's phone and looking at them.
There are parental controls (if it's a child account) if you're concerned about sensitive/explicit content:
iOS 17 (coming this Fall) is increasing controls that would allow you to hide sensitive/explicit photos and videos by default to avoid unsolicited content from being seen.
My best recommendation is to have an open line of communication with your child of trust and understanding.