If you have rebooted the iPhone, the first login after boot asks for the passcode. Logins during normal use (from standby, for example) after that first login will accept FaceID (or touch ID, depending on iPhone model.)
That I know but in her case... This is the second time, well the first time she had a brain fart when I was going to update and now same thing. Guess it will be another wipe and restore. Thanks.