According to whas11.com,
16 year-old Tabitha Comstock's wish has came true which is to see the set of Phineas and Ferb. Comstock is a major fan of the series and was able to meet the creators as well as some of the cast.
During her visit, she was able to see an episode in production, as well as doing voicework for a character in an upcoming episode.
Congragulations Tabitha for making your dream come true.
And Congragulations Phineas and Ferb for helping her make her dream come true.