Is it possible to track location of a text message sender on my kid's phone?

Hey there. Unfortunately, you can’t track the location of a text sender directly—that would be a major privacy breach. It’s one of the things I appreciate about iPhones; Apple really locks that stuff down for security.

Your best bet is to use the Find My app through Family Sharing to see your kid’s location. It’s built-in and super reliable, unlike some of those sketchy third-party apps you might find on Android.