This kid heard somewhere how much tee work the batbusters do so she has been doing a lot on her own. Any kind of bad habbits you should look out for using the tee.
Carl
Careful she doesn't counter rotate/turn her upper torso,chest away back toward the catcher. Since the head tends to turn down to look at the tee, the torso becomes comfortable turned back toward the catcher in a way that would be less likely to happen with the head looking toward the pitcher. That's a common flaw peculiar to the tee.