Twins, but...

Then 'Sarah' knew a wish she could make. "I wish that I'll be known as Athena again, that you would change to look just like me, and we'd be twin sisters." A flash of light later, and two identical blonde cheerleader girls stood there. In the new reality, Athena and Sarah were twin sisters. But they both remembered being the original Sarah, and neither of them remembered being the original Athena. Everyone **else** thought they were twin sisters. Except Jon, of course, who was protected. Jon remembered the goth Athena, not the twin sisters, but was unaware they now shared memories.