Enable Geofencing for Shared Sessions

I've just set this up for myself and my misses. However, I've noted that you can't seem to set up geofences for shared sessions. This would be useful as sometime she has to go out with little warning, and I don't know if she has without looking it up. We also happen to live in different countries, so keeping track of each other can be a little fun >.<

Can this be added for shared sessions please? Possibly even with an option to turn the feature on/off for the shared link? Annnnd maybe be able to have geofencing post normal notifications?