The Rise of the Phoenix (Marvel/Captain America/Agent Carter)

Alexis Jane Morgan is an intelligent 18 year old girl who by some miracle manages to score herself a job with the one and only Howard Stark.
She wants to help her country in the war, the war that took her father's life. She wants to design and build weapons that can help defend the brave soldiers and the men who fought by her father's side until his death.
But when the war ends and Captain America is lost, Howard begins to try and recreate the serum that changed Steve Roger's life forever, but when Howard leaves Alexis to find the missing Captain America he entrusts her with continuing his work. One clumsy accident later and Alexis wakes up in hospital a month after, but she isn't the same.