My headcanon is that Nat isn't on Tony's side because of Tony, she's actually on Pepper's side, because she was friends with Pepper before she was friends with Steve.
My thing with Nat (and ink-phoenix and I were talking about this one the phone the other day) is that sheās shortchanged in pretty much every film ever. Even though sheās not a love interest in TWS and yes, she does have some amazing moments of her own, she is still very much there to support Steveās story, which is why the idea of her siding with Steve (or Tony via Pepper) irks me as it currently stands. Itās that it once again sets her on a path that is defined by her relationship to someone else and what she can do for them, not because it is a decision we have seen her come to on her own.
The other Avengers are a little different, but Nat is the one character who has spent a significant time with both Steve and Tony and who you could legitimately argue might go either way on the topic for her own personal reasons,. But we havenāt had enough character development from her for any choice she makes to be 100% about her and not just which teammate she is siding with or against.
Tell me sheās siding for the legislation because sheās been betrayed by the system she thought was fighting for good and she wants to see a greater level of accountability in place because yes, the likes of SHIELD will always be necessary but they NEED to have controls in place.
Tell me sheās siding against it because sheās been betrayed by the system she thought was fighting for good and she doesnāt trust any governing body to act without some level of corruption and sheās done being used by people.
Tell me something, and then show it to me. Donāt just say āsheās on Tonyās sideā or āsheās on Capās sideā because thatās just a cop out and I am sick and tired of seeing her be used as a prop with lines when she is so much more.
I ranted, I apologize. Please donāt think I am aiming this at you personally!