Doctor Allison Carter is a retired DoD Agent, researcher and medical doctor. She was also the Director of Global Dynamics for a while.
Allison and her brother grew up in a family of scientists, who approached life rationally. They did love and support her, but they disliked sentimentality and unnecessary displays of affection.
At age 17, Ally began studying medicine, which was the only subject she and her parents could agree on. She was an impressive young woman; empathic, intelligent and hard-working. Her professors foretold a bright future for her.
Shortly after her 21st birthday, Allison started dating a fellow student. That was her first serious relationship. She fell in love, and they got married four years later. Tragically, her husband died less than one year after the wedding, leaving her alone with their unborn child. Shaken and lost, Allison took her father's advice and reclaimed her maiden name before her son's birth. Kevin Blake was born on November 18th 1997, when his mother was 26.
As a child, Kevin was diagnosed with autism, which didn't make their life any easier. One of the few people the boy dared to open up to was Doctor Nathan Stark. Due to his bond with her child, Allison got to know Nathan, and the three of them soon fell into a comfortable rhythm. They became a family - first emotionally, and then legally when Allison married Nathan.
Unfortunately, her second marriage wasn't meant to last either. They signed the divorce papers in 2004, when Kevin was 7 years old. Ally and Nathan remained separated for a few years, however, they eventually revived their relationship. They were going to get married once more in 2008 - on the day that ended up being Nathan's last. He never made it to the ceremony, because he was dematerialized while he repaired a hole in the space time continuum. A little later, in a wicked twist of fate, Allison found out that she was pregnant - and just like her firstborn, her second child would never get a chance to meet their father. Roughly eight months after Nathan's death, Allison gave birth to Jenna Stark.
in 2010, Allison, Jack, Henry, Jo and Fargo were sent on an involuntary trip back in time, and when they returned to the present, they found themselves in a new timeline. The most significant change for Ally was certainly her son - because somehow, Kevin was no longer autistic. Instead, he had become a bright and outgoing teenager, always chasing the next adventure or challenge.
Aside from that, Allison and Jack shared their first kiss while they were stuck in the past, taking a first real step towards their romantic relationship. In the end, they had a spontaneous wedding in 2012, making Allison the wife of Jack and the stepmother of Zoe Carter. Not too long afterwards, Ally found out that she was pregnant with Lacey - the first and only child of hers who got to know both of her parents growing up.