I don't know if it changed in recent builds but she doesn't really teleport behind you: if you are quick enough and/or don't have your back fully to her you'll see that she actually runs (fairly quickly) behind you and then basically "sticks" to your back.
Easiest ways to notice is when you, for example, enter a classroom and she's quietly following you: if the light switch is in view (but you're not facing it) you'll see that she makes a dash to the light, switches it off and attempts to dash back to you.
The other way is if you walk through doors and she's standing just next to them (it's rare, I think, but she's got me a few times like this) you can either see her just before she "sticks" on you or if you turn slowly so that you see her just a few centimeters and/or an inch into your view. (she musn't do that "ahh" reaction or else your line of sight is meeting with hers and she'll now attack you)