I believe she interned for him.
I think Hillary took one of Saul Alinsky’s Community Organizer courses and Saul offered her a position, but she decided to go to law school instead. They remained friends until his death. She wrote her Wellesly College senior paper on the Alinsky Method. While in law school she did an internship with former Communist Party USA lawyer Robert Treuhaft’s law firm as a reward for hard work trying to derail the prosecution of the murder trial of a Black Panther (also a Marxist organization)