The actress' feet probably don't get more than 10 or 15 feet above the stage. Assuming that the actress is 5 feet tall(probably underestimating, that would put her head 15-20 feet in the air, plenty high to provide the illusion of levetation. This also allows the actress' face to be seen, rather than being blocked by the proscenium(perhaps 25 feet tall in some venues?)
"Wherever you go... I'll be right there. When you get your own private kick in the ass, just remember: it's a present from me to you."
Rose's dying words to Louise