Her tea doesn’t cause the gift, but it does cause Ali to get pretty effed up to the point where she hits her head which then somehow magically yields her the gift.
In What Men Want, Erykah Badu’s character is a psychic and maybe drug dealer who gives Taraji P. Henson’s Ali the tea that starts her on the long journey.
There’s no reason that the mystical and weird Sister could not really be the conduit for other characters to receive the gift in a follow-up.
Sister later reveals to Ali that she tried the tea herself, but that it didn’t work in the same way for her as it did for Ali.