I managed to work around this issue as i experienced the same thing recently.
Create a custom firewall rule which prevents your laptop or macbook from communicating to other devices on your girlfriends ip range, except the default gateway.
For example, on a 192.168.0.0 network most default gateways are 192.168.0.1. Block all outbound TCP connections to 192.168.0.2 - 192.168.0.254
Worked first time for me.