find family sharing on iphone

Hi this article should help you locate family sharing.

On your iPhone, iPad, or iPod touch

1. Go to Settings > [your name] > Family Sharing.
2. Tap Add Member.
3. Enter your family member's name or email address and follow the onscreen instructions.
4. Choose whether you'd like to send an invitation via Messages or to invite them in person. Then follow the onscreen instructions.

https://support.apple.com/en-us/HT201088

Settings>Your Name>Family Sharing.