

Max: The Sequel, Phoebe officially started her training to become a superhero. As a reward for saving Max, the Hero League awarded Phoebe a superhero cape. In A Hero Is Born, Phoebe exposed the family's secret to her best friend Cherry so that Cherry can babysit Chloe while Phoebe saves Max from the evil villains led by King Crab. Phoebe didn't give up on getting the superhero cape. Max blew up the chance for both of them to get the superhero cape. She let Max take the credit so that she doesn't get in trouble. Unfortunately, she ruined her chances when she sneaked to a rooftop party and used telekinesis to save someone from falling. However, by Cape Fear, she realized that she needed to put more effort in training after her best friend from Metroburg got her Superhero Cape. In Thunder Van, she started training to join the Hero University but after she had Max messed up in the Thunder Van, she decided to take it slow. Phoebe showed her desire to train and become a superhero and her dad offered to train her. However, her school life hasn't been smooth because she often finds herself in trouble with Principal Bradford who hates both Phoebe and Max. She helped organize school dance in The Amazing Rat Race and the junior prom in Thundermans: Secret Revealed. She tried for school choir in Pretty Little Choirs but Veronica attacked her with spitballs. She ran for class president in You Stole My Thunder, Man but she ended up losing it to Max. She was the captain of the Math Bowl in Report Card. Since joining the school, Phoebe has been very involved in most school activities. However, Cherry remains to be Phoebe's best friends.

By the junior year, she managed to become friends with one of the cheerleaders, Maddy and her friend Roxy. Any attempt to become friends with Winnie Lee ended up in humiliation until Phoebe stopped trying. Madison became Phoebe's enemy after making Phoebe fail cheerleader tryouts and trying to humiliate Cherry. One of the popular girls, Veronica, attacked her with spitballs during choir solo auditions. However, at the same time, she still struggled to fit in with the popular girls. Phoebe was a perfect match for the group because she was already one of the smartest students. Phoebe also made other friends like Sarah and Ashley through Sarah's group of smart students after joining them for Math Bowl in Report Card. At first, the friendship was a challenge because Phoebe had to lie to her best friend to keep the family's superpowers a secret. At the school, Phoebe made her first friend, Cherry Seinfeld who is still her best friend. In Hiddenville, Phoebe goes to Hiddenville High with Max. In 2013, the Thundermans moved to Hiddenville to live a normal life. Phoebe was born and raised in Metroburg when their parents were still active superheroes. Her younger siblings are Billy, Nora and Chloe Thunderman, and they are the Thunder Kids. She was born 20 seconds earlier than Max. Phoebe is the oldest daughter of Barb and Hank Thunderman, alongside her twin brother Max Thunderman.
