Zenobia tried to clear her path to Hollingsworth by essentially giving Priscilla to Westervelt. This is why she asks forgiveness in the end. Although she doesn’t clearly admit it, Zenobia is ashamed of herself. She’s not a villainous person by nature, and her decision to hand Priscilla over to Westervelt was uncharacteristic of her. Priscilla’s love makes her blind to Hollingsworth’s faults, but she notably doesn’t deny that his love for her might soon burn out. On some level, Priscilla knows Hollingsworth doesn’t love her like she loves him.