Vandersloot tied the record, held by Ticha Penicheiro, at 16 on a drive to the basket, drawing two defenders and finding Ruthy Hebard under the hoop for a 89-74 lead with 3:22 remaining.
After a brief rest on the bench, Vandersloot found her wife Allie Quigley in the corner for a 3-pointer to break the record. And two possessions later, Vandersloot connected with Quigley again for a 3-pointer and a 25-point lead.
Penicheiro, who reached 16 assists in 1998 and 2002, tweeted a congratulatory note to Vandersloot after the game.
Vandersloot finished with 13 points and 18 assists, and Quigley added 19 points for Chicago (11-6). Gabby Williams and Kahleah Copper each scored 21 points.
Teaira McCowan had 15 points and 11 rebounds for Indiana (5-11). Candice Dupree had 14 points and Natalie Achonwa 13.
The game was originally scheduled to be played last Wednesday, but was postponed because the WNBA players decided not to play that night or the next night in solidarity with their NBA counterparts following the weekend police shooting of Jacob Blake.