Adding girlfriends phone as a presence sensor to my ST?

You create your own network id number. It can be anything, it just can’t duplicate any existing device number. You may want to also try this: [Release] Virtual Presence Plus (presence controlled by a virtual switch) as it appears to be a switch. That would allow you to write an IFTTT applet, like: if her phone connects to your router, then switch on virtual presence switch. That’s what I’m thinking could work.