Episode #5.3 - S5-E3
Continuity mistake: At the end of the episode when Peter has seen Stacey undressed, Sue comes up the stairs and Ben is standing on the landing behind her. The position of Ben's arms is different in the close-up of Sue than it is in the wider shot from from behind Stacey.
Answer: Acording to all online sources, her birthday is 30th August 2001. It's also documented that in Season 5 she is in year 7 and 11 years old. If her birthday is 30th August, she will start year 7, 2 days after her 11th Birthday so this is correct.
Ssiscool ★