Given the story limitations imposed on us on the PC in F4, I still think we can have some back story to our characters before they got married and had a kid.
Male: Christopher Stark, An ex heir to multi billion company that shut down when he refused to become the CEO of that company when his father died. He is tech wiz that has done some work for the military either in combat or helping his scientist friends advance power armor. He enjoys having a normal life, but at times he craves action due to his military background.
Female: Diana or Kallen, A young girl that was raised by a military father who secretly taught her basic survival skills, how to use a gun and melee weapons. She was the top of her class and consider the strongest person in college due to her advancing what she was taught by her late father by learning from her ex blacks ops uncle. She soon settled down with her man and had a kid.