Abigail, Amanda and Amy (Erica, Jaclyn and Nicole Dahm) are identical triplet villainesses from the Relic Hunter episode Nothing But The Truth.
They have a restaurant in San Francisco and are currently taking cooking classes at a French cooking school, which is believed to be the current location of an ancient artefact called The Chalice Of Truth. Three of the protagonists, Sydney, Nigel and Stewie, are also at the cooking school, taking classes with the intention of locating the chalice.
Amanda seems to be nice, Amy is very flirty and Abigail seems to dislike men, she ends up kneeing Nigel and throwing him to the ground just for speaking to her.
The triplets are contacts inside the school for a group of thugs on the outside, who are also after the chalice. They secretly relay information to the thugs about the heroes and also attempt to obtain the chalice.
At a dinner inside the school, it becomes apparent to all the relevant parties that the chalice is in the room amongst some replicas. Stewie attempts to swap a fake for the real one, but the thugs on the outside cut the power inside the school. During the commotion Amanda grabs the chalice and makes a run for it, Sydney and Nigel chase after her and Amanda and Sydney end up fighting for a short while. Amanda gets a couple of kicks in before Nigel throws a bowl of olives on the floor at Amanda's feet. She slips on the olives while attempting another kick and falls to the floor unconscious. Presumably after this the triplets face some kind of justice, although it isn't shown on screen.