Can I be your Captain? (Steve Rogers fanfic)

So Jackie is a normal 24 year old girl who I also the younger sister of New Yorks very own Tony Stark. Who is amazingly brilliant and lives in the Stark Tower. I guess you also know him as Iron Man? Haha. Of course you do. Everything is going well when she finds out she's gonna be a new agent for S.H.I.E.L.D. But then she meets the marvelous Captain America(Steve Rogers) he might quite possible be in love with her.