Fionia Gunderson is a girl whom Manny Delgado falls in love in "My Funky Valentine".
She reads a Valentine poem that Manny wrote for her, which she loves it, but a boy called Ted Durkas tells her that he wrote the poem to win Fionia's heart. Manny explains this to Mitchell and Cameron and decide to go to the restaurant where Fiona and Ted are having a date to get Fionia back for Manny. Cam runs block for Manny by getting Ted away from the table. Manny is able to tell Fionia he really wrote the poem, but Ted comes back and shoves Manny away. Mitch then defends Manny by using the speech he was going to use from the case which makes Cam happy. Ted finally admits that he didn't write the poem, but also tells Fionia that he had those feelings but didn't know how to express them. She thinks it's sweet, and Manny and Mitch get out of the restaurant because they think she is a loon.
In "Truth Be Told", she is mentioned by Jay at the funeral of Manny's pet turtle, Shel Turtlestein.