Are you sharing an AppleID? If so, this is the cause of your problem.
If all your devices are sharing a common AppleID for iCloud, you’ll encounter all kinds of issues with unintentional and/or unwanted sharing of sensitive/private information (including Messages).
The Golden Rule: Don’t share an AppleID between users. Each user should have their own AppleID for their own exclusive use - linked to their own primary email (and secondary/recovery email addresses and trusted telephone numbers).
You would be best advised to separate your digital identities and configure a new AppleID for other users. If setting-up AppleID for a minor, you should set-up Family Sharing first - and create the AppleID for your Daughter from there.
You may find this information to be helpful with setting-up an AppleID for a minor - and considering appropriate controls:
Apple for Kids - Official Apple Support
Help your child set up an iPhone, iPad, or iPod touch - Apple Support
Family Sharing and Apple ID for your child – Apple Support
After separating your identities, should you choose to do so, you can continue to selectively share purchased Apple Services, Subscriptions, Apps and Media using Apple’s Family Sharing features. Also consider the use of Parental Control features.
Use parental controls on your child's iPhone, iPad and iPod touch – Apple Support
Use Screen Time on your iPhone, iPad or iPod touch – Apple Support
Set up Screen Time for a family member on iPad - Apple Support
Family Sharing - Apple
Set up Family Sharing – Apple Support
Share App Store, iTunes Store and Apple Books purchases with Family Sharing – Apple Support
https://www.imore.com/how-set-up-family-sharing-iphone-ipad