If you use location sharing with family and friends, you’ll want to make sure iOS is sharing from the right device.
There are lots of reasons you may want to share your location through the Messages app or Find My Friends. For example, sharing a location is a lot faster than manually typing out a location to someone. If you have more than one iOS device, maybe an iPhone and an iPad for example, you may want to change which one is used for default location sharing.
Location sharing works for almost all devices but in order to use some features of location sharing, like Family Sharing, you’ll have to be running iOS 8 or newer. It’s also worth noting that if you’re in a Family Sharing group, anyone in your group can see all your devices via the Find My iPhone app. Following the steps below will choose your default device for constant tracking in certain apps, like Messages. I’d recommend setting the default device as whatever one you carry around with you. For most people, this will be their iPhone.
How to pick what iPhone or iPad is used for sharing your location
Source: iMore