User blog comment:Bobtherandomguy/The New assumption/@comment-3251190-20110103032148

Here's what I think. Candace, Phineas, and Ferb are siblings.

Jeremy and Suzy are siblings.

Albert and Irving are siblings.

Stacy and Ginger might be siblings.

Gretchen and Carl might be siblings.

Django and Jenny might be siblings.

Holly might possibly be siblings with Coltrane.

All the kids are friends and they have teenage siblings who are also friends, I think.