I don't think there's anything objectionable for a 9 year old except a few (like two or three max) instances of profanity. Spider-Man and Iron Man both say the s-word at different points in the movie but that's it.
I really only had three issues with the movie: first, to keep it from being a bloated 3 hour mess they dealt with Black Panther, Spider-Man, Ant-Man etc. joining Team Stark or Team Cap very quickly. I wish they'd given more time to introducing the new characters but they didn't do a bad job of it.
Second, there is zero reason for Hawkeye to be in this movie. Jeremy Renner mailed in his performance so hard.
Third, some of the quips, one-liners etc. fell flat to my ears, or they were delivered in too rapid a succession. I could have done with a little bit less wit being tossed back and forth during the big fight at the airport. All the jokes being made, the "are we still friends?" "Depends on how hard you hit me" etc. That drained the tension some, made it obvious that they weren't truly trying to take each other out. I think they realized it because then they had one of the superheroes get seriously injured at the end of the fight, bringing back the gravity. Of course by the end of the movie he's okay.
Not as good as the Winter Soldier but better than any other MCU movie, better than both Avengers, all 3 Iron Men movies, both Thors, etc. Loved the portrayals of Spider-Man and Ant-Man and the dialogue written for them in particular.
).
