Candace could be a main character. Since Ferb is sick, she might be in a bit of a dilemma. On one hand, she still has her urge to bust Phineas if he does something out of the ordinary while taking care of Ferb. But on the other hand, she also cares about her brother and might be more lenient or even helpful.
Definitely not a true story. Phineas and Ferb is full of imaginative and creative elements that couldn't happen in real life. It's all about having fun and adventures in a made-up world.
The story of Phineas and Ferb is based on the adventures and creativity of two stepbrothers during their summer vacation. It's filled with wild inventions and fun escapades.
Phineas and Ferb is not based on real events. It's a creation of the show's writers and animators, full of creative and fantastical elements for entertainment.