Sickled feet - any good pointers how to unlearn this habit?

I'm trying to help a student from sickling her feet. She's well aware and frustrated that she does this especially when she's inverted holding a pose or learning a new trick/spin. Unconsciously her foot turns in. I don't know of any specific exercises or technique to help prevent this other than leg lifts, pointed toe, turn out from the hip, and focus on the pinky toe pulling away to the outside.