Agent Carter is played by Hayley Atwell in both the short run series and in the MCU. The series picks up in post WWII NYC where Carter is assigned with SSR (Strategic Scientific Reserve) the forerunner of S.H.I.E.L.D.
Carter is working in a office full of sexist slobs while coming to grips with the loss of her one true love, Steve Rogers. When Howard Stark, father of Ironman's Tony Stark, is declared an enemy of the state he seeks out Carter to help clear his name. Stark puts his butler Jarvis at Peggy's disposal and to act as intermediary while he is on the run.
The show enjoys a 8.5 rating at IMDB and was a lot of fun to watch. The costumes are excellent and there are guest appearances by actors who've played in the Marvel movies. Add to that the movie tie ins and this was one fun series.
Stark's butler Jarvis is, of course, the inspiration for Tony Stark's AI J.A.R.V.I.S. but could he be more than that? IMDB show Atwell as being in Avengers: Age of Ultron, certainly it's a flashback. I'm guessing but here it is, Ultron create's the Android body for the Vision. J.A.R.V.I.S. jumps in before Ultron can, then we learn that the J.A.R.V.I.S. AI is the consciousness of Jarvis complete with memories. So perhaps Jarvis will relate to Rogers aka Captain America his exploits with Carter. Hey, they brought Colson back to life! It's not that big a leap when IMDB lists Paul Bettany as both Jarvis and The Vision.
Does Tony Stark have a half-sister in the Avengers? If you've watched Agent Carter you know that it could be possible. During the series run Carter and SSR encounter a woman from the black widow program with whom Stark spent an evening. We may find out that she is the mother of Natasha Romanoff.
Will Carter be back for a second run? I'd bet on it.