"I wish Jason still existed," Erika said, holding the stone (Jason was her half-brother). But nothing happened. Puzzled, she made another wish. "I wish I knew why my last wish wasn't granted." This time, it did glow.
Apparently, Jason hadn't been erased from existence when Erika wished her stepmother (Sharon) was more like her real mother. Her "former" stepmother had married some other guy and had Jason with him instead.
In this new reality, Jason was now the son of Sharon and ...