Automatically Share Your Hotspot
You can set up your Personal Hotspot so that your devices and your family devices can automatically connect as needed. When set up, a nearby device without a network connection can choose to connect to yours automatically to share cellular data. While your devices will do this by default, shared family devices can be set up in the Settings app under the Personal Hotspot settings. Tap Family Sharing, enable it, and configure your family members so they can join automatically or by asking.