The Storm (9-15, 6-9 Iowa Conference) pulled away with a 12-5 run to start the fourth quarter, picking up their 32nd straight wain against Central.
Simmons -- who transferred to Simpson following her freshman year at Central -- continued her late season tear, adding three steals and three assists. She is averaging 15.3 points in her last six games.
Simpson led 54-47 after the third before Claire Johnson converted a layup and Gallagher made a pair of free throws. Gallagher added a 3-pointer, Britney Boland knocked down a jumper and Botkins canned her fourth trey to stretch the lead to 68-52 with 4:56 to play.
Emily Dine scored 21 points on 7-for-15 shooting from beyond the arc for the Dutch (9-14, 2-12).
The Storm kept their hopes for an IIAC Tournament berth alive with the win. Simpson is currently tied for the sixth and final tournament spot with Nebraska Wesleyan with just one game remaining.
Simpson hosts Luther on Wednesday, Feb. 15 in the Play4Kay Breast Cancer Awareness game. The Norse (14-9, 10-4) beat Loras 50-47 on Saturday.