The theme song for Jennibelle is Firework as performed by Peter Hollens
This song is speaking to Jennibelle (JB) as opposed to her signing it. JB knows that she is better than just who she is yet JB is content with the simple life of video games and babysitting.
Firework applies before JB takes the name of Anya. In a sense this is Anya telling JB that she can do amazing things if she believed in herself.
“I think I’m going to puke.” – JB, Phoenix Element Normality Twisted, Chapter 6