What happened to Julianna from LazyTown?

She left the show when she out-grew the role and hasn’t done anymore acting since, instead focusing full-time on her studies. Julianna reportedly attended Columbia University where she studied Occupational Therapy.

Why was Julianna Rose Mauriello replaced?

The role of Stephanie was performed by Julianna Rose Mauriello in seasons 1 and 2. In 2011, Julianna confirmed she would be leaving LazyTown, since she has grown too old to play the role of Stephanie. So she was replaced by Chloe Lang for seasons 3 and 4. Stephanie was also played by Kimberly Pena in LazyTown Live!

Why did LazyTown end?

A fifth season was planned, but due to the fact that the studio where Lazy Town was filmed burned down and Stefan Karl Stefanson died in 2018, it was decided to cancel the season, and the episode was the very last.