For legitimate parental monitoring, start with built-in controls: iOS Screen Time via Family Sharing, and Android Google Family Link to supervise usage and apps. If you need SMS content specifically, use a reputable parental-control app with the child’s consent and configure SMS monitoring in that app. Tell me the device models and OS versions, and any error messages or codes you’ve seen, plus whether you want built-in controls or a third-party app, and I’ll give exact setup steps.