Not necessarily, it’s a function of how the mesh works and if packets are lost then the command will be incomplete. For a true thermostat automation you will need an app which is a closed loop and monitor the status and takes corrective action if mesh degradation is detected.
Here a few that have such a closed loop system:
[RELEASE] 5-2 Day Programmable Thermostat Scheduler (Weekday, Weekend) with Remote Temperature Sensor for each Schedule
[RELEASE] Mode Based Thermostat - Control Multiple Thermostats Temperature / Remote Temperature Sensors when Changing Modes
[RELEASE] Motion Sensor Thermostat with Remote temperature sensors, Presence detection and Schedules
You can change the mode of the house when she leaves and arrives and then create an automation based on mode to change the thermostat. Again you’ll run in the lack of closed loop verification there, one of the apps above is a modes based thermostat which may solve that issue for you (plus you can use remote temperature sensors to create it a truly smart thermostat, e.g. at night focus the temperature on your bedroom with a standalone temperature sensor and during the day use the thermostat built in sensor)