I'm asking about
the Scarlet Witch.
She (and another character) worked with Hydra before the Avengers took the sceptre. When they found out Ultron was planning to destroy the world, they decided to help the Avengers save it.
I can't help but think that if any Hydra agents had been there, they'd probably have tried to stop Ultron as well. This wouldn't make them "good", it would just be because they and the Avengers had a common enemy, as Hydra probably wouldn't want the world to be destroyed either. Even saving the citizens wouldn't mean they stopped being Hydra, it would just mean they're less "evil" than others. Their main goals could still be the same.
Yet Hawkeye clearly said he considered her an Avenger, and in the end she seems to be part of the team. Was she shown to have changed her mind about any of Hydra's goals?