This is happening because you are using the same Apple ID for everyone in your Family.
To stop getting calls on all of your devices using same Apple ID, just turn off the Calls from iPhone setting on that device.
See the setup section above for details.
- On your iPhone, go to Settings > Phone > Calls on Other Devices, then turn on Allow Calls on Other Devices.
- On your iPad or iPod touch, go to Settings > FaceTime, then turn on Calls from iPhone.
- On your Mac, open the FaceTime app, then choose FaceTime > Preferences. Click Settings, then select Calls From iPhone.
Learn about Family sharing with different Apple IDs--> Set up Family Sharing - Apple Support