The notion of mourning doesn’t exist in the Marvel Cinematic Universe.
I really love Civil War but they are few things in this movie that really managed to annoyed me.
Steve kiss Sharon, only a few days after Peggy’s death. I don’t mind Staron. I found them even cute. Seriously, I’m happy that Steve founds another girl but that was like the worst timing EVER. The best would have been to not kill Peggy or maybe wait for Infinity War —when Steve/Sharon is already established— to kill her. So yeah, that part wasn’t managed very well.
BUT the worst is Wanda. I’m so upset ! Like I know that AOU was a years ago but idk, I would have excepted a brief glimpse of her grief after the loss of her twin brother, Pietro. Maybe a necklace (similar to the one that Natasha carries in TWS) or just a sentence. Especially with the big part the Sokovia events take in Civil War, a simple mention would have fit perfectly with the rest of the movie IMO. But no, it’s like Pietro Maximoff never existed and his death is already totally forgotten. The only —very vague—mention of him was made by Clint. Basically he owes Wanda a “debt”(=Pietro’s sacrifice). That’s all. Hmm…it would have been better to have nothing rather than this shit.