She is Candace's little sister
Phineas and Ferb: Forever Summer
She and her friends and family are older and the setting is in the future in this series. Since her brother is married to Candace, Suzy is now her sister-in-law.
She is a minor antoginist in this show. She appears in Epsiode 3, where she is mean at beginning then good, but then she says "It's so hard being nice *alarm rings* Oh! yay time to be mean again".
She appears in the television special, Jenny With a Chance: Christmas Special.
She does not appear in season 2.
She made a cameo in the series, but is often mentioned as series progressed.
Jeremy Johnson is Suzy's older brother.
Candace Flynn is Jeremy's girlfriend and Suzy's nemisis
Jimmy Nelson is Suzy's crush, She respects him because he will not let anyone date his sister much like she will not let anyone date Jeremy.
Cain Rangle Johnson is her older cousin, but like Candace, he knows that Suzy is a "devil".
Wilson, character from Dark Adventures greatly despise Suzy than anyone else, even more so than Candace Flynn despite never interact each other. He despised her as he saw her harm Candace every time Candace dates Jeremy once Jeremy not around once.