Debra Coleman
Slightly different situation, but Sheryl Crow plays bass on a number of her songs in live performances.
Also, in the “not when they’re in their usual band” mode like Tina Weymouth, John Taylor of Duran Duran sang lead and played bass in both Neurotic Outsiders and with Terroristen, his “solo” era projects.
Rob Grill from The Grass Roots
Fat Mike from NoFX