Hello Shortfuse_,
Thanks for posting this in the Apple Support Community. We understand that you have ideas about being able to disable or delete the Messages app. We’re happy to guide you.
Use Screen Time on your iPhone, iPad or iPod touch -- While you can’t delete the Messages application, you can use Screen Time to limit her access to content you don’t approve of. Make sure you review the information in this article to under how Screen Time works. You can also use Family Sharing to configure the settings from your own device: Set up Family Sharing
Use parental controls on your child's iPhone, iPad, and iPod touch -- Scroll dow to the bottom of Screen Time and choose Content & Privacy Restrictions. Choose Content Restrictions and set the limit that works best for you.
We love hearing about things you’d like to see in future updates. If you haven’t already, you can leave feedback here: Product Feedback
Cheers!