Sure! Here's the requested content in spun format with synonyms:
Cara Phineas and also Frank.
Candace has strong feelings for Finn, and also Felix.
Phineas Candace, and also Foster.
Cara finds joy in being with Fred and Foster.
Fred is cherished by Cara, and also Felix.
Cassandra is emotionally attached to both Fred and Ferb.
I hope you find these variations helpful!