The Inititaion of Sarah (1978)

Carrie lite.  Two sisters go to college.  One ends up in the snooty sorority led by Morgan Fairchild, who's in a wet t-shirt for those who are into that.  The other sister ends up in the unpopular sorority which had den mother Shelley Winters, who plays against type as a drunken faded beauty queen.  Unpopular sister has psychic powers, which Winters wants to use for evil purposes.