Rosemary was a former Pentagon data analyst who was eventually ordered to get to know the solider known as Jack-the man later known as Raiden-by the Patriots AI, and trick him into a rescue mission on the “Big Shell” rig, where they could gather valuable data to help enforce their rule by creating a similar operation to Solid Snake’s Shadow Moses.
The two met on April 30th, 2007, and started flirting by talking about-and watching-the 1933 version of King Kong, arguing whether it was the Chrystler or Empire State building that Kong climbed in the movie.
The two then discovered they worked in the same military complex (What an amazing coincidence) and started dating, although at times their relationship was strained by Jack’s coldness and aloof nature at times. Two years passed.
Eventually, Jack was assigned to infiltrate the Big Shell, and Rosemary, suprisingly, served as mission support. During the operation, there were many revelations, such as Jack’s past and the true nature of the mission-and also that she was pregnant. Her transmission then faded, although a simulated version of her-a Patriot AI-eventually taunted Raiden as he fought Solidus Snake, causing Raiden to wonder if Rose was real, or simply just false information fed to him by the Patriots. At the end however, Snake revealed to Raiden that Rose was indeed, real.
However, the threats of both the Patriots, and Jack’s dark past caused the couple to drift apart a bit (Raiden also lost a good chunk of his body, becoming a cyborg ninja). She also seemed to miscarry their child. In an unexpected move, she married Colonel Campbell, which further divided the rift between the Colonel and his daughter, Meryl.
Rose re-emerged at her “husband’s” request to help Solid Snake with stress during his fight with Liquid Ocelot. After the Patriots were defeated, she finally was able to speak with Raiden again. Raiden, recovering from his injuries and getting some more cosmetic skin grafts for a more human appearance, was introduced to his son John, and her miscarriage and marriage to Campbell had both been lies designed to protect them from the Patriots.
The two got married, and were still married around the time of 2018 when Raiden fought the Desperado group.