But once she began to KILL IT and basicaly proved that she is the most talented 12-year-old girl in existence, he realized how wrong he was. Advertisement Tweet Pin It Related Posts But Beau Dermott’s performance of the song almost puts broadway stars to shame. Don’t believe us? Check her out herself (and be ready for goosebumps). And Simon being Simon, made a face that suggested that Beau was going to wish she never opened her mouth. Check out the reactions of these little girls in the audience. They knew they were in the presence of something special.