You can make an Emergency SOS call on iPhone X the same way as before, by rapidly pressing the side button 5 times. To do this it must be enabled in Settings -> Emergency SOS, where you can toggle "Call with Side Button."
What you are saying is when the iPhone was inside her purse the iPhone rapidly pressed the side button 5 times? Before it calls the iPhone makes huge sound for 5 Seconds. She did not even hear that sound. OK
- If she accidentally called emergency services, she could have ended the call. Tap
", then confirm that you want to stop calling.
What exactly do you mean by "Locked"? Because by making an emergency call your iPhone does not get locked.
Use Emergency SOS on your iPhone - Apple Support
https://support.apple.com/en-us/HT208076