For one, ensure the vehicle is double locked, by pressing the lock button twice on the fob.
Use the remote app to keep track of her, ensure she is locked and then afterwards put it into Guardian Mode underneath the security section of the Home Screen. Set a date and time for how long you want it enabled.
I work for an airline and do it everytime I park it in our employee lot. Just make sure it's disabled or off by the time you get back into the car. It's not a super big deal if it isn't, but it sends you a remote alert saying guardian mode detected something, when in reality it's just you getting back into the car earlier than expected.
Just keep an eye on vehicle through the app while you're gone to see its location and if anything was triggered. I believe it won't alert authorities, you have to with the number provided if something does happen.
Anyways, just piece of mind.
As far as battery, should be fine, I never have issues with mine and I could be gone for at least 5 days at a time.