How can I know if someone is tracking my iPhone? Or are there any ways I can find out

I had a friend, that knows things I never mention to her. And she is becoming really creepy about my life. I though maybe she is tracking my iPhone but I don't know what can I do?

Hmm

Turn off GPS & change passwords associated with your iPhone device on Apple website

Not likely. Are you so important that other people would want to track your every move? I don't think so.

You CAN'T know that it is being tracked.

Back up anything you want to save (photos, etc) from your phone to another device or the cloud and perform a system reset on your iPhone. If there's malware stealthily installed that will remove it. In addition, change your passwords to everything, especially your apple account since that's tied to Find My iPhone and that's a way to track you. Also be mindful of what you post to social media.

Turn off gps & change passwords associated with your iphone device on apple website