Penny Ken (Bridgit Mendler) is a one time character who appears in "Wrong Song" as Nick Lucas's love interest for that episode.
At the beginning of the episode, we find out that Nick is falling fast and hard for Penny despite being warned to slow down by Kevin. Nick goes crazy trying to write a song for Penny, and performs for her "Give Love A Try".
Penny misunderstands that Nick wrote the song about her and instead think that it is a song that he wrote for her to sing. Penny then invites Nick to watch her perform at CBDB's where Penny announces that she will be singing the song Nick wrote for her. Nick then is saddened to find out that she already has a boyfriend, after she dedicates the song to her boyfriend.
The next day, Penny says she did not see Nick the night before, and he says he was in the back. Nick tells Penny to record in the studio at their house. Penny does, and right before recording, Nick storms down to the kitchen, where Joe and Kevin follow him. Nick admits that Kevin and Joe were right about moving too far, too fast.
The boys go back upstairs, where Penny tells Nick that she broke up with Jimmy because he hated the song. The two sing a duet on " Give Love A Try".