User blog comment:Phin68/Who do you ship? Ferb Vanessa or Ferb Gretchen/@comment-1331763-20090907133125

@Ard11230: If I can recall correctly, the Creators of the show did not give a specific age for both Phineas and Ferb, so we cannot really say for certain about the age differece between the two characters. By comparison, Vanessa looks MUCH older than Ferb, which has been a concern for me about this pairing.