During and after her studies she appeared in multiple Belgian musicals such as "Cinderella", "The Wizard of Oz", "Sleeping Beauty", "Pinocchio", "Robin Hood" and "Peter Pan", in which she played the role of Tiger Lily and understudy for Wendy.
Since she has been playing the role of "Vicky Muys", the girlfriend/wife of Rikki Dilliarkis (Steven De Lelie) in the Belgian TV series Lili & Marleen on vtm.
Isa is a teen with too much time on her hands, too many boyfriends and who needs a lot of parental advice, even though she's not always willing to take it.
Ever since she started her studies, Vanderheijden has been doing leading roles & protagonist parts in Belgian musicals.
She also sings in the KETNET-band and the Kids Power Team, which is specifically aimed for children.