Jetstream is one of the two tritagonists and a superheroine in the film Sky High.
Jetstream is a world famous superhero who has the power of supersonic flight and is a master of unarmed combat. Her alter ego is Josie Stronghold, a realtor, the wife of Steven Stronghold, and the mother of a teenage boy named Will. She takes her ‘cover job’, as a real estate agent, the "family business" very seriously.
She is also a devoted wife and mother. At the beginning of the film, she reminisced about when Will was a little kid, to which Will replied, embarrassed, "Mom!" She also appeared to be worried about Will too much, until Steve told her to stop treating him like a baby.
In the film, Josie is first seen having breakfast with Will and Layla Williams. She and Steve are then called on a mission to defeat a giant robot terrorizing the city.