The One After the Superbowl, part 1 - S2-E12
Continuity mistake: The first time Phoebe performs at the library this takes place at the same time Joey is on his date. During Joey's date, it's night time. But, when Phoebe is singing, it's broad daylight outside. (00:07:20)
Chosen answer: It's certainly not out of the question. That being said, Sophie is only David's half-sister, as they have different fathers, so if the jumper traits came from David's father, or from some genetic combination of his parents, then Sophie would not share his abilities.
Tailkinker ★