Realistically, I don't know how much "development" you can expect for basically any of the original Avengers going forward. Unless BP is going to become "Black Panther featuring Steve Rogers", there will be a Falcon-in-Ant-Man like cameo at most. Sharon probably won't show up. The focus of the universe is shifting to Panther/Strange/GOTG/Ant-Man for awhile.
The next team movie are the Infinity War movies, which will have 5,000 characters. I doubt much focus will be on the main characters' romances at all. It will be like Pepper/Tony and Thor/Jane, forgotten or severely sidelined in the team movies, except Steve/Sharon didn't get the chance to be developed by either of those because they didn't do it in any of the Cap movies. Sharon will probably show up to fight at some point, I imagine, but unless they really decide to make her one of the core characters in another movie, CW was probably the most screentime she'll have going forward. I guess anything's possible though, you never know.