No, she doesn't drive at all. She's hooked her phone up to my car stereo so she can play the kids their playlist on her spotify so nothing sinister there. As I say it was her that mentioned it, if she was tracking me then surely she'd keep discreet about it??
Apologies I should have said 'use your car' which you have clarified ... in which case my earlier post explains that her phone will only show the location of the car when she is in it and you arrive at your destination and it disconnects from the stereo/bluetooth.
When you are in the car alone her phone will not track you as 'where's my car' app is only logging the location of her phone and not the car or your phone.
You therefore were never at risk.