Capable Dick and Stevie
I think it would be fun if there are moments where the others realize how competent Dick and Stevie are as heroes since they can be underestimated often.
One possibility is Dick having to subdue the others in the Batfamily because of an enemy or a mission and he needs to take them down to save them, during a time when Bruce is off world. This would include him mildly poisoning Cassie, who is a better fighter than him, and taking down the others, who have underestimated him somewhat. At the end, there can be a scene where he's talking to everyone and maybe apologizing, while they are in the aftermath of him completely demolishing the,. This could instill a new sense of respect for him and his capabilities, as well as showing them why it's good that he's not their enemy. Damian could be proud of Dick the entire time.
On Stevie's end, it could be more of a build up over time as the Avengers get to see who Stevie is as a whole as she gets more comfortable with them as friends. There will be specific moments during missions where she gets to show them what she's capable of while being humble about her accomplishments. They can also discover that she's had some incredible experiences in her life. Stevie could have possibly met some incredible people, like Albert Einstein, Billie Holiday, and Alan Turing.